urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was called after the response had been read and decompressed partially (compression algorithm did not matter here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a single operation. This could result in excessive resource consumption (high CPU usage and massive memory allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.

The remote Redhat Enterprise Linux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:28000 advisory.

    Python is an interpreted, interactive, object-oriented programming language, which includes modules,     classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to     many system calls and libraries, as well as to various windowing systems.

    Security Fix(es):

    * urllib3: urllib3: Denial of Service due to excessive HTTP response decompression (CVE-2026-44432)

    * urllib3: urllib3: Information disclosure via cross-origin redirects forwarding sensitive headers     (CVE-2026-44431)

    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 these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:27929 advisory.

    Python is an interpreted, interactive, object-oriented programming language, which includes modules,     classes, exceptions, very high level dynamic data types and dynamic typing. Python supports interfaces to     many system calls and libraries, as well as to various windowing systems.

    Security Fix(es):

    * urllib3: urllib3: Denial of Service due to excessive HTTP response decompression (CVE-2026-44432)

    * urllib3: urllib3: Information disclosure via cross-origin redirects forwarding sensitive headers     (CVE-2026-44431)

    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 these issues but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the python-urllib3-1.26.5-8.el9 build changelog.

  - urllib3 is an HTTP client library for Python. From 1.23 to before 2.7.0, cross-origin redirects followed     from the low-level API via ProxyManager.connection_from_url().urlopen(..., assert_same_host=False) still     forward these sensitive headers. This vulnerability is fixed in 2.7.0. (CVE-2026-44431)

  - urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the     whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when     the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was     called after the response had been read and decompressed partially (compression algorithm did not matter     here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a     single operation. This could result in excessive resource consumption (high CPU usage and massive memory     allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.
    (CVE-2026-44432)

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 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8379-1 advisory.

    It was discovered that urllib3 incorrectly handled cross-origin redirects in ProxyManager. A remote     attacker could possibly use this issue to obtain sensitive information. (CVE-2026-44431)

    It was discovered that urllib3 incorrectly handled decompression of specially crafted responses. A remote     attacker could possibly use this issue to cause urllib3 to consume resources, leading to a denial of     service. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-44432)

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

  - urllib3 is an HTTP client library for Python. From 2.6.0 to before 2.7.0, urllib3 could decompress the     whole response instead of the requested portion (1) during the second HTTPResponse.read(amt=N) call when     the response was decompressed using the official Brotli library or (2) when HTTPResponse.drain_conn() was     called after the response had been read and decompressed partially (compression algorithm did not matter     here). These issues could cause urllib3 to fully decode a small amount of highly compressed data in a     single operation. This could result in excessive resource consumption (high CPU usage and massive memory     allocation for the decompressed data) on the client side. This vulnerability is fixed in 2.7.0.
    (CVE-2026-44432)

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

ID	Name	Product	Family	Severity
321983	RHEL 10 : python-urllib3 (RHSA-2026:28000)	Nessus	Red Hat Local Security Checks	high
321979	RHEL 10 : python3.14-urllib3 (RHSA-2026:27929)	Nessus	Red Hat Local Security Checks	high
321968	CentOS 9 : python-urllib3-1.26.5-8.el9	Nessus	CentOS Local Security Checks	high
318624	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : urllib3 vulnerabilities (USN-8379-1)	Nessus	Ubuntu Local Security Checks	high
314743	Linux Distros Unpatched Vulnerability : CVE-2026-44432	Nessus	Misc.	high

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CVE-2026-44432

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Tenable Plugins

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