libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

The remote SUSE Linux SLED15 / SLED_SAP15 / SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2925-1 advisory.

    This update for curl fixes the following issues

    - CVE-2026-4873: connection reuse ignores TLS requirement (bsc#1262631).
    - CVE-2026-8286: wrong STARTTLS connection reuse (bsc#1268402).
    - CVE-2026-8458: wrong reuse for different services (bsc#1268407).
    - CVE-2026-8924: traling dot domain super cookie (bsc#1268409).
    - CVE-2026-8927: env-set cross-proxy Digest auth state leak (bsc#1268413).
    - CVE-2026-9079: stale proxy password leak (bsc#1268415).
    - CVE-2026-9080: UAF after pause in socket callback (bsc#1268416).
    - CVE-2026-9545: exposing HTTP/3 early data (bsc#1268417).
    - CVE-2026-9547: SSH improper host validation (bsc#1268420).
    - CVE-2026-10536: HTTP/2 stream-dependency tree UAF (bsc#1268422).
    - CVE-2026-12064: proto-default skips SSH verification (bsc#1268427).

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

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

The remote SUSE Linux SLES15 / SLES_SAP15 host has packages installed that are affected by multiple vulnerabilities as referenced in the SUSE-SU-2026:2926-1 advisory.

    This update for curl fixes the following issues

    - CVE-2026-8286: wrong STARTTLS connection reuse (bsc#1268402).
    - CVE-2026-8458: wrong reuse for different services (bsc#1268407).
    - CVE-2026-8924: traling dot domain super cookie (bsc#1268409).
    - CVE-2026-8927: env-set cross-proxy Digest auth state leak (bsc#1268413).
    - CVE-2026-9079: stale proxy password leak (bsc#1268415).
    - CVE-2026-9080: UAF after pause in socket callback (bsc#1268416).
    - CVE-2026-9545: exposing HTTP/3 early data (bsc#1268417).
    - CVE-2026-9547: SSH improper host validation (bsc#1268420).
    - CVE-2026-10536: HTTP/2 stream-dependency tree UAF (bsc#1268422).
    - CVE-2026-12064: proto-default skips SSH verification (bsc#1268427).

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

Note that Nessus has not tested for these issues 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 multiple vulnerabilities as referenced in the openSUSE-SU-2026:21272-1 advisory.

    This update for curl fixes the following issues

    - CVE-2026-8286: wrong STARTTLS connection reuse (bsc#1268402).
    - CVE-2026-8458: wrong reuse for different services (bsc#1268407).
    - CVE-2026-8924: traling dot domain super cookie (bsc#1268409).
    - CVE-2026-8927: env-set cross-proxy Digest auth state leak (bsc#1268413).
    - CVE-2026-9079: stale proxy password leak (bsc#1268415).
    - CVE-2026-9080: UAF after pause in socket callback (bsc#1268416).
    - CVE-2026-9545: exposing HTTP/3 early data (bsc#1268417).
    - CVE-2026-9547: SSH improper host validation (bsc#1268420).
    - CVE-2026-10536: HTTP/2 stream-dependency tree UAF (bsc#1268422).
    - CVE-2026-12064: proto-default skips SSH verification (bsc#1268427).

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

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

The remote Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8487-1 advisory.

    Andrew Nesbitt discovered that curl could reuse an existing live connection during STARTTLS-based     connection upgrades even when the TLS configuration did not match. A remote attacker could possibly use     this issue to cause curl to use an unintended TLS configuration. (CVE-2026-8286)

    Muhamad Arga Reksapati discovered that curl incorrectly reused connections for Negotiate-authenticated     requests when different services were involved. A remote attacker could possibly use this issue to access     resources authenticated for another service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS,     Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-8458)

    It was discovered that curl incorrectly handled cookie parsing in certain circumstances. A remote attacker     could possibly use this issue to set cookies that would be transmitted to unrelated third-party domains.
    This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu     24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-8924)

    Joshua Rogers discovered that curl could double-free a GSASL context when handling SASL authentication. A     remote attacker could possibly use this issue to cause a denial of service, or execute arbitrary code.
    This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS.
    (CVE-2026-8925)

    Joshua Rogers discovered that curl could select the wrong password from a .netrc file when a username was     specified in the URL without a password. A remote attacker could possibly use this issue to obtain     sensitive information. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-8926)

    Ady Elouej discovered that curl did not clear proxy authentication state between requests when reusing a     handle with environment-variable proxy configuration. A remote attacker could possibly use this issue to     obtain sensitive credentials. (CVE-2026-8927)

    Guannan Wang, Zhanpeng Liu, Jiashuo Liang, and Guancheng Li discovered that curl did not properly clear     proxy authentication credentials when instructed to do so. A remote attacker could possibly use this issue     to obtain sensitive credentials. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS.
    (CVE-2026-9079)

    Joshua Rogers discovered that curl contained a use-after-free when curl_easy_pause() was called within the     event-based socket callback. A remote attacker could possibly use this issue to cause a denial of service     or possibly execute arbitrary code. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS.
    (CVE-2026-9080)

    Eunsoo Kim discovered that curl could send early data on a resumed TLS session before enforcing     certificate verification failure. A machine-in-the-middle attacker could possibly use this issue to obtain     sensitive information. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-9545)

    Joshua Rogers discovered that curl did not properly reject host key type mismatches when using the SSH key     callback for SCP and SFTP transfers. A machine-in-the-middle attacker could possibly use this issue to     impersonate a trusted server. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, Ubuntu 25.10,     and Ubuntu 26.04 LTS. (CVE-2026-9547)

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

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

The version of libcurl installed on the remote host is 7.43.0 prior to 8.21.0. It is, therefore, affected by an improper connection reuse vulnerability:

  - libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated     ones, even when they are set to use different services. (CVE-2026-8458)

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.

  - libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated     ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so     that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a     range of criteria must be met. Due to a logical error in the code, a request that was issued by an     application could wrongfully reuse an existing connection to the same server that was authenticated using     different services. (CVE-2026-8458)

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

ID	Name	Product	Family	Severity
326957	SUSE SLED15 / SLES15 Security Update : curl (SUSE-SU-2026:2925-1)	Nessus	SuSE Local Security Checks	critical
326933	SUSE SLES15 Security Update : curl (SUSE-SU-2026:2926-1)	Nessus	SuSE Local Security Checks	critical
326418	openSUSE 16: curl / curl-fish-completion / curl-zsh-completion / libcurl-devel / etc (openSUSE-SU-2026:21272-1)	Nessus	SuSE Local Security Checks	critical
324983	Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : curl vulnerabilities (USN-8487-1)	Nessus	Ubuntu Local Security Checks	critical
323013	libcurl 7.43.0 < 8.21.0 Wrong Negotiate Connection Reuse	Nessus	Misc.	medium
322464	Linux Distros Unpatched Vulnerability : CVE-2026-8458	Nessus	Misc.	medium

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