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Echo: soupsieve: security update to 2.9.0

medium Tenable Self-Hosted Container Security Plugin ID 464885

Description

There are packages installed that are affected by a vulnerability referenced in the following CVE:

 - Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9,
 selector_iter in src/soupsieve/css_parser.py trims the raw selector with RE_WS_END, an end-anchored WSC
 whitespace-and-comment expression used with search(), so the regular expression engine retries a greedy
 scan at every starting offset. An attacker-controlled valid selector containing a long internal whitespace
 run, or a selector containing a long CSS comment run followed by another token, causes quadratic CPU work
 before tokenization. User-controlled selectors can reach the path through soupsieve.compile() and
 BeautifulSoup.select(), while applications using only hard-coded selectors are unaffected. This root cause
 is separate from the IDENTIFIER and VALUE backtracking vulnerability because the cost occurs in
 RE_WS_END.search during trimming rather than token matching. The resulting CPU consumption can hold the
 Python GIL, exhaust workers, and stall a service without causing memory corruption or code execution. The
 issue is fixed in version 2.9. (CVE-2026-85999)

Solution

Update the soupsieve library and its related packages to version 2.9.0 or later.

See Also

https://advisory.echohq.com/cve/CVE-2026-85999

Plugin Details

Severity: Medium

ID: 464885

Version: Revision 1.1

Type: Local

Published: 10/2/2026

Updated: 10/3/2026

Supported Sensors: Tenable Cloud Security, Tenable Self-Hosted Container Security

Risk Information

VPR

Risk Factor: Low

Score: 1.2

Percentile: 0.01

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2026-85999

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

Exploit Ease: No known exploits are available

Patch Publication Date: 9/19/2026

Vulnerability Publication Date: 9/17/2026

Reference Information

CVE: CVE-2026-85999