nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.

The version of Tencent Linux installed on the remote TencentOS Server 3 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the TSSA-2026:0905 advisory.

    Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

    CVE-2026-58055:
    nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-     Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection     headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in     the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote MiracleLinux 9 host has packages installed that are affected by a vulnerability as referenced in the AXSA:2026-1622:04 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the MiracleLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-102505 advisory.

    nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-     Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection     headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in     the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote MiracleLinux 8 host has packages installed that are affected by a vulnerability as referenced in the AXSA:2026-1576:03 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the MiracleLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 9 host has packages installed that are affected by a vulnerability as referenced in the nghttp2-1.43.0-8.el9 build changelog.

  - nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-     Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection     headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in     the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.
    (CVE-2026-58055)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2026-55804 advisory.

    [1.33.0-6.3]
    - fix HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests     (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:55804 advisory.

    libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 (HTTP/2) protocol in C.

    Security Fix(es):

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:55804 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote RockyLinux 8 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:55804 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 9 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:54662 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 10 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2026:54650 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote RockyLinux 10 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:54650 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote RockyLinux 9 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2026:54662 advisory.

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 10 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2026-54650 advisory.

    [1.68.0-3.2]
    - fix HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests     (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 9 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2026-54662 advisory.

    [1.43.0-6.2]
    - fix HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests     (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:54662 advisory.

    libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 (HTTP/2) protocol in C.

    Security Fix(es):

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 10 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:54650 advisory.

    libnghttp2 is a library implementing the Hypertext Transfer Protocol version 2 (HTTP/2) protocol in C.

    Security Fix(es):

    * nghttp2: nghttp2: HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1     Upgrade requests (CVE-2026-58055)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-91dd0c29d6 advisory.

    - fix HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests     (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has a package installed that is affected by a vulnerability as referenced in the FEDORA-2026-084c991d17 advisory.

    - fix HTTP Request/Response Smuggling and Response-Queue Poisoning via ambiguous HTTP/1.1 Upgrade requests     (CVE-2026-58055)

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by a vulnerability as referenced in the SUSE-SU-2026:3153-1 advisory.

    This update for nghttp2 fixes the following issue

    - CVE-2026-58055: HTTP/1.1 Upgrade request can lead to HTTP request smuggling and cross-client response-     queue poisoning       (bsc#1269489).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 host has packages installed that are affected by a vulnerability as referenced in the SUSE- SU-2026:3154-1 advisory.

    This update for nghttp2 fixes the following issue

    - CVE-2026-58055: HTTP/1.1 Upgrade request can lead to HTTP request smuggling and cross-client response-     queue poisoning       (bsc#1269489).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote openSUSE 16 host has packages installed that are affected by a vulnerability as referenced in the openSUSE- SU-2026:21302-1 advisory.

    This update for nghttp2 fixes the following issue

    - CVE-2026-58055: HTTP request/response smuggling via upgrade request with `Content-Length` (bsc#1269489).

Tenable has extracted the preceding description block directly from the SUSE security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-8495-1 advisory.

    It was discovered that the nghttp2 nghttpx proxy incorrectly handled HTTP/1.1 Upgrade requests that     included a Content-Length header and body. A remote attacker could possibly use this issue to perform HTTP     request and response smuggling attacks against backend services.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - nghttp2's nghttpx proxy through 1.69.0 forwards an HTTP/1.1 Upgrade request that also carries a Content-     Length header and body onto reusable keep-alive backend connections, re-adding the Upgrade and Connection     headers while passing Content-Length verbatim. A backend that resolves the resulting ambiguous message in     the attacker's favor enables HTTP request/response smuggling and cross-client response-queue poisoning.
    (CVE-2026-58055)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
341111	TencentOS Server 3: nghttp2 (TSSA-2026:0905)	Nessus	Tencent Local Security Checks	Local	medium
339027	MiracleLinux 9 : nghttp2-1.43.0-6.el9_8.2 (AXSA:2026-1622:04)	Nessus	Miracle Linux Local Security Checks	Local	medium
338540	Unity Linux 20.1070a Security Update: nghttp2 (UTSA-2026-102505)	Nessus	Unity Linux Local Security Checks	Local	medium
338058	MiracleLinux 8 : nghttp2-1.33.0-6.el8_10.3 (AXSA:2026-1576:03)	Nessus	Miracle Linux Local Security Checks	Local	medium
337898	CentOS 9 : nghttp2-1.43.0-8.el9	Nessus	CentOS Local Security Checks	Local	medium
337879	Oracle Linux 8 : nghttp2 (ELSA-2026-55804)	Nessus	Oracle Linux Local Security Checks	Local	medium
337338	RHEL 8 : nghttp2 (RHSA-2026:55804)	Nessus	Red Hat Local Security Checks	Local	medium
337145	AlmaLinux 8 : nghttp2 (ALSA-2026:55804)	Nessus	Alma Linux Local Security Checks	Local	medium
337099	RockyLinux 8 : nghttp2 (RLSA-2026:55804)	Nessus	Rocky Linux Local Security Checks	Local	medium
335444	AlmaLinux 9 : nghttp2 (ALSA-2026:54662)	Nessus	Alma Linux Local Security Checks	Local	medium
335440	AlmaLinux 10 : nghttp2 (ALSA-2026:54650)	Nessus	Alma Linux Local Security Checks	Local	medium
335427	RockyLinux 10 : nghttp2 (RLSA-2026:54650)	Nessus	Rocky Linux Local Security Checks	Local	medium
335420	RockyLinux 9 : nghttp2 (RLSA-2026:54662)	Nessus	Rocky Linux Local Security Checks	Local	medium
335399	Oracle Linux 10 : nghttp2 (ELSA-2026-54650)	Nessus	Oracle Linux Local Security Checks	Local	medium
335398	Oracle Linux 9 : nghttp2 (ELSA-2026-54662)	Nessus	Oracle Linux Local Security Checks	Local	medium
335260	RHEL 9 : nghttp2 (RHSA-2026:54662)	Nessus	Red Hat Local Security Checks	Local	medium
335255	RHEL 10 : nghttp2 (RHSA-2026:54650)	Nessus	Red Hat Local Security Checks	Local	medium
334455	Fedora 43 : nghttp2 (2026-91dd0c29d6)	Nessus	Fedora Local Security Checks	Local	medium
333546	Fedora 44 : nghttp2 (2026-084c991d17)	Nessus	Fedora Local Security Checks	Local	medium
328906	SUSE SLED15 / SLES15 Security Update : nghttp2 (SUSE-SU-2026:3153-1)	Nessus	SuSE Local Security Checks	Local	medium
328905	SUSE SLES12 Security Update : nghttp2 (SUSE-SU-2026:3154-1)	Nessus	SuSE Local Security Checks	Local	medium
326667	openSUSE 16 Security Update : nghttp2 (openSUSE-SU-2026:21302-1)	Nessus	SuSE Local Security Checks	Local	medium
325013	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : nghttp2 vulnerability (USN-8495-1)	Nessus	Ubuntu Local Security Checks	Local	medium
323595	Linux Distros Unpatched Vulnerability : CVE-2026-58055	Nessus	Misc.	Local	medium

Detections

Analytics

CVE-2026-58055

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Tenable Plugins

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