PYSEC-2026-4171 Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)

Summary Before tokenizing, selectoriter trims leading/trailing whitespace and comments by running two regexes over the whole raw selector with .search. The trailing one, REWSEND = re.compiler'WSC$', is anchored only at the end $, not the start. Because .search retries the pattern at every offset,...

Soup Sieve: Polynomial-time ReDoS (O(n²)) in the `IDENTIFIER` / `VALUE` selector sub-patterns

Summarysoupsieve compiles CSS selector strings with a set of hand-written regular expressions. The shared IDENTIFIER sub-pattern also embedded in VALUE, and therefore in attribute selectors places two adjacent quantified groups over overlapping character classes: ?:classA|ESC+?:classB|ESC, where...

Soup Sieve: Polynomial-time ReDoS (O(n²)) in the whitespace/comment trimming regex `RE_WS_END` (triggers on VALID selectors)

SummaryBefore tokenizing, selectoriter trims leading/trailing whitespace and comments by running two regexes over the whole raw selector with .search. The trailing one, REWSEND = re.compiler'WSC$', is anchored only at the end $, not the start. Because .search retries the pattern at every offset, ...

PYSEC-2026-4170 Soup Sieve: Polynomial-time ReDoS (O(n²)) in the `IDENTIFIER` / `VALUE` selector sub-patterns

Summary soupsieve compiles CSS selector strings with a set of hand-written regular expressions. The shared IDENTIFIER sub-pattern also embedded in VALUE, and therefore in attribute selectors places two adjacent quantified groups over overlapping character classes: ?:classA|ESC+?:classB|ESC, where...

PT-2026-105915

Summary Before tokenizing, selector iter trims leading/trailing whitespace and comments by running two regexes over the whole raw selector with .search. The trailing one, RE WS END = re.compiler'WSC$', is anchored only at the end $, not the start. Because .search retries the pattern at every...

PT-2026-105914

Summary soupsieve compiles CSS selector strings with a set of hand-written regular expressions. The shared IDENTIFIER sub-pattern also embedded in VALUE, and therefore in attribute selectors places two adjacent quantified groups over overlapping character classes: ?:classA|ESC+?:classB|ESC, where...

CLEANSTART-2026-IA02205 Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4

CVE-2026-85999 affects multiple packages. Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. See references for individual vulnerability details...

CLEANSTART-2026-YC00032 Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4

CVE-2026-86000 affects multiple packages. Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. See references for individual vulnerability details...

Security Bulletin: IBM InfoSphere Optim Archive Viewer is affected by multiple vulnerabilities in soupsieve (CVE-2026-49476, CVE-2026-49477)

Summary Multiple vulnerabilities in the soupsieve CSS selector parsing library CVE-2026-49476, CVE-2026-49477 used by IBM InfoSphere Optim Archive Viewer have been addressed by upgrading the component to version 2.9.1 on Windows and version 2.9.2 on Linux. Vulnerability Details CVEID:CVE-2026-494...

CLEANSTART-2026-PS59368 Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4

CVE-2026-86000 affects multiple packages. Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. See references for individual vulnerability details...

CVE-2026-86000

A flaw was found in Soup Sieve, a CSS selector library. An attacker can craft a malicious CSS selector that, when processed by the library, leads to excessive CPU consumption. This occurs due to a polynomial-time regular expression denial of service ReDoS vulnerability in the selector parser...

CVE-2026-85999

A flaw was found in Soup Sieve, a CSS selector library. A remote attacker can provide a specially crafted CSS selector containing long whitespace or comment runs. This can cause excessive CPU consumption during selector trimming, leading to a Regular Expression Denial of Service ReDoS by stalling...

CVE-2026-86000: Uncontrolled Resource Consumption

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. Prior to 2.9, the selector parser in src/soupsieve/cssparser.py defines IDENTIFIER with adjacent quantified groups over overlapping character classes, and VALUE embeds IDENTIFIER for attribute selectors. When an...

OESA-2026-3762 python-soupsieve security update

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. It aims to provide selecting, matching, and filtering using modern CSS selectors. Soup Sieve currently provides selectors from the CSS level 1 specifications up through the latest CSS level 4 drafts and beyond though...

OESA-2026-3621 python-soupsieve security update

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. It aims to provide selecting, matching, and filtering using modern CSS selectors. Soup Sieve currently provides selectors from the CSS level 1 specifications up through the latest CSS level 4 drafts and beyond though...

OESA-2026-3620 python-soupsieve security update

Soup Sieve is a CSS selector library designed to be used with Beautiful Soup 4. It aims to provide selecting, matching, and filtering using modern CSS selectors. Soup Sieve currently provides selectors from the CSS level 1 specifications up through the latest CSS level 4 drafts and beyond though...

CVE-2026-79770

A flaw was found in Nokogiri. A remote attacker can inject specially crafted CSS selectors into methods such as Nodecss or Nodeatcss. This injection can lead to regular expression denial of service ReDoS due to exponential regex backtracking, causing the application to become unresponsive...

SUSE CVE-2026-79770

Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifier tokenization. Attackers can inject adversarial CSS selectors into methods like Nodecss, Nodeatcss, and Searchablesearch to cause...

Linux Distros Unpatched Vulnerability : CVE-2026-79770

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector tokenizer affecting string-literal and identifi...

GHSA-5JHF-FPP7-V2PV Duplicate Advisory: Nokogiri CSS selector tokenizer has regular expression backtracking

Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-c4rq-3m3g-8wgx. This link is maintained to preserve external references. Original Description Nokogiri versions before 1.19.3 contain regular expression denial of service vulnerabilities in the CSS selector...