VulnerableCode Package Details - pkg:pypi/justhtml@1.17.0

Search for packages

Vulnerability	Summary	Fixed by
VCID-ze6z-2zm7-rud9 Aliases: GHSA-r8cj-3554-33mr	justhtml introduces denial-of-service hardening ## Summary `justhtml` `1.18.0` fixes multiple low-severity denial-of-service hardening issues in CSS selector handling and linkification. These issues are availability concerns. They do not allow script execution, data disclosure, or sanitizer bypass by themselves. ## Affected versions - `justhtml` `< 1.18.0` ## Fixed version - `justhtml` `1.18.0` released on May 4, 2026 ## Impact ### CSS selector handling Applications that evaluate attacker-controlled selector strings, or that run selector-based transform pipelines over attacker-controlled documents, could consume disproportionate CPU or memory. The affected selector patterns included oversized selectors, large selector lists, oversized compound selectors, long combinator chains, deeply nested functional pseudo-classes such as `:not(...)`, repeated attribute/class token matching over large values, repeated sibling or ancestor scans, repeated positional pseudo-class work, and `:contains(...)` over large descendant text. Programmatically constructed malformed DOM graphs could also trigger non-terminating or duplicate traversal in some selector paths, including cyclic/shared child graphs, cyclic parent chains, and cyclic text traversal for `:contains(...)`. ### Linkification Attacker-controlled text containing punctuation-heavy input or URL candidates ending in long runs of unmatched closing brackets could cause repeated rescanning and consume disproportionate CPU when linkification was enabled. ## Default configuration Ordinary sanitization of parsed HTML with the default `JustHTML(..., sanitize=True)` configuration is not expected to expose untrusted users to selector injection, because selectors are normally supplied by application code. The main risk areas are: - applications that accept selector strings from untrusted users and pass them to `query(...)`, `matches(...)`, or selector-based transforms - custom transform or sanitization pipelines that run selector matching over very large untrusted documents - applications that construct or mutate DOM trees programmatically from untrusted structure - applications that enable `Linkify(...)` over attacker-controlled text ## Fixes in 1.18.0 `1.18.0` adds generalized selector resource controls and removes several repeated-work hot paths: - shared selector limits for parse and match operations - structural caps for selector length, selector lists, compound selectors, complex selectors, and parse depth - match-operation and string-byte budgets - per-query matcher state for caches and cycle guards - precomputed or cached ancestor, sibling, positional, attribute-token, text-content, `:not(...)`, `:empty`, and `:nth-child(...)` work - consistent enforcement across public parsing, `query(...)`, tag-only query fast paths, transform selector compilation, and sanitization transform matching - linkification hardening for punctuation-heavy inputs and trailing bracket trimming ## CWE mapping - CWE-400: Uncontrolled Resource Consumption - CWE-407: Inefficient Algorithmic Complexity - CWE-835: Loop with Unreachable Exit Condition ## Recommended action Upgrade to `justhtml` `1.18.0`. If users cannot upgrade immediately: - do not pass untrusted selector strings to `query(...)`, `matches(...)`, or selector-based transforms - restrict the size of untrusted documents before selector matching or linkification - avoid constructing programmatic DOM graphs from untrusted structure - avoid enabling `Linkify(...)` on very large attacker-controlled text ## Credit Discovered during an internal security review of `justhtml`.	1.18.0 Affected by 0 other vulnerabilities.

Vulnerability

Summary

Fixed by

VCID-ze6z-2zm7-rud9
Aliases:
GHSA-r8cj-3554-33mr

justhtml introduces denial-of-service hardening ## Summary `justhtml` `1.18.0` fixes multiple low-severity denial-of-service hardening issues in CSS selector handling and linkification. These issues are availability concerns. They do not allow script execution, data disclosure, or sanitizer bypass by themselves. ## Affected versions - `justhtml` `< 1.18.0` ## Fixed version - `justhtml` `1.18.0` released on May 4, 2026 ## Impact ### CSS selector handling Applications that evaluate attacker-controlled selector strings, or that run selector-based transform pipelines over attacker-controlled documents, could consume disproportionate CPU or memory. The affected selector patterns included oversized selectors, large selector lists, oversized compound selectors, long combinator chains, deeply nested functional pseudo-classes such as `:not(...)`, repeated attribute/class token matching over large values, repeated sibling or ancestor scans, repeated positional pseudo-class work, and `:contains(...)` over large descendant text. Programmatically constructed malformed DOM graphs could also trigger non-terminating or duplicate traversal in some selector paths, including cyclic/shared child graphs, cyclic parent chains, and cyclic text traversal for `:contains(...)`. ### Linkification Attacker-controlled text containing punctuation-heavy input or URL candidates ending in long runs of unmatched closing brackets could cause repeated rescanning and consume disproportionate CPU when linkification was enabled. ## Default configuration Ordinary sanitization of parsed HTML with the default `JustHTML(..., sanitize=True)` configuration is not expected to expose untrusted users to selector injection, because selectors are normally supplied by application code. The main risk areas are: - applications that accept selector strings from untrusted users and pass them to `query(...)`, `matches(...)`, or selector-based transforms - custom transform or sanitization pipelines that run selector matching over very large untrusted documents - applications that construct or mutate DOM trees programmatically from untrusted structure - applications that enable `Linkify(...)` over attacker-controlled text ## Fixes in 1.18.0 `1.18.0` adds generalized selector resource controls and removes several repeated-work hot paths: - shared selector limits for parse and match operations - structural caps for selector length, selector lists, compound selectors, complex selectors, and parse depth - match-operation and string-byte budgets - per-query matcher state for caches and cycle guards - precomputed or cached ancestor, sibling, positional, attribute-token, text-content, `:not(...)`, `:empty`, and `:nth-child(...)` work - consistent enforcement across public parsing, `query(...)`, tag-only query fast paths, transform selector compilation, and sanitization transform matching - linkification hardening for punctuation-heavy inputs and trailing bracket trimming ## CWE mapping - CWE-400: Uncontrolled Resource Consumption - CWE-407: Inefficient Algorithmic Complexity - CWE-835: Loop with Unreachable Exit Condition ## Recommended action Upgrade to `justhtml` `1.18.0`. If users cannot upgrade immediately: - do not pass untrusted selector strings to `query(...)`, `matches(...)`, or selector-based transforms - restrict the size of untrusted documents before selector matching or linkification - avoid constructing programmatic DOM graphs from untrusted structure - avoid enabling `Linkify(...)` on very large attacker-controlled text ## Credit Discovered during an internal security review of `justhtml`.

1.18.0
Affected by 0 other vulnerabilities.

Vulnerability	Summary	Aliases
VCID-pe3n-8tcx-5bb5	justhtml has sanitization bypass in custom policies and programmatic DOM ## Summary `justhtml` `1.17.0` fixes multiple security issues in sanitization, serialization, and programmatic DOM handling. Most of these issues affected advanced or custom configurations rather than the default safe path. ## Affected versions - `justhtml` `<= 1.16.0` ## Fixed version - `justhtml` `1.17.0` released on April 19, 2026 ## Impact ### Custom SVG / MathML sanitization policies Custom policies that preserved foreign namespaces could allow dangerous content to survive sanitization, including: - active HTML integration points such as SVG `<foreignObject>`, MathML `<annotation-xml encoding="text/html">`, SVG `<title>` / `<desc>`, and MathML text integration points - mutation-XSS parser-differential payloads that looked inert in memory but became active HTML after reparse - SVG `filter="url(...)"` attributes that could trigger external fetches These issues affected: - `JustHTML(..., sanitize=True)` with custom foreign-namespace policies - `sanitize()` / `sanitize_dom()` - low-level terminal `Sanitize(...)` transform execution ### Preserved `<style>` handling Constructor-time sanitization and explicit `Sanitize(...)` transforms did not fully match `sanitize()` / `sanitize_dom()` when custom policies preserved `<style>`. That could leave resource-loading CSS such as `@import` or `background-image:url(...)` in sanitized output from HTML string input. ### Programmatic DOM serialization Programmatic `script`, `style`, and `Comment(...)` nodes could still serialize into active markup in some edge cases. This could affect applications that build or mutate DOM trees directly before calling `to_html()` or `to_markdown(html_passthrough=True)`. ### Cache mutation and DOM cycle handling Two lower-severity hardening fixes were included: - compiled sanitize-pipeline caches could be mutated after warming and weaken later sanitization - parent/child cycles in programmatic DOM trees could cause infinite loops in operations such as `to_html()` and `sanitize_dom()` ## Default configuration Most of the issues above did not affect ordinary parsed HTML with the default `JustHTML(..., sanitize=True)` configuration. The main risk areas were: - custom policies that preserve SVG or MathML - custom policies that preserve `<style>` - programmatic DOM construction or mutation - low-level direct sanitizer/transform APIs ## Recommended action Upgrade to `justhtml` `1.17.0`. If users cannot upgrade immediately: - avoid preserving SVG or MathML for untrusted input - avoid preserving `<style>` for untrusted input - avoid mutating programmatic DOM trees with untrusted `script`, `style`, or comment content - avoid mutating warmed policy internals or sanitizer caches ## Credit Discovered during an internal security review of `justhtml`.	GHSA-vrx2-77f2-ww34

Vulnerability

Summary

Aliases

VCID-pe3n-8tcx-5bb5

justhtml has sanitization bypass in custom policies and programmatic DOM ## Summary `justhtml` `1.17.0` fixes multiple security issues in sanitization, serialization, and programmatic DOM handling. Most of these issues affected advanced or custom configurations rather than the default safe path. ## Affected versions - `justhtml` `<= 1.16.0` ## Fixed version - `justhtml` `1.17.0` released on April 19, 2026 ## Impact ### Custom SVG / MathML sanitization policies Custom policies that preserved foreign namespaces could allow dangerous content to survive sanitization, including: - active HTML integration points such as SVG `<foreignObject>`, MathML `<annotation-xml encoding="text/html">`, SVG `<title>` / `<desc>`, and MathML text integration points - mutation-XSS parser-differential payloads that looked inert in memory but became active HTML after reparse - SVG `filter="url(...)"` attributes that could trigger external fetches These issues affected: - `JustHTML(..., sanitize=True)` with custom foreign-namespace policies - `sanitize()` / `sanitize_dom()` - low-level terminal `Sanitize(...)` transform execution ### Preserved `<style>` handling Constructor-time sanitization and explicit `Sanitize(...)` transforms did not fully match `sanitize()` / `sanitize_dom()` when custom policies preserved `<style>`. That could leave resource-loading CSS such as `@import` or `background-image:url(...)` in sanitized output from HTML string input. ### Programmatic DOM serialization Programmatic `script`, `style`, and `Comment(...)` nodes could still serialize into active markup in some edge cases. This could affect applications that build or mutate DOM trees directly before calling `to_html()` or `to_markdown(html_passthrough=True)`. ### Cache mutation and DOM cycle handling Two lower-severity hardening fixes were included: - compiled sanitize-pipeline caches could be mutated after warming and weaken later sanitization - parent/child cycles in programmatic DOM trees could cause infinite loops in operations such as `to_html()` and `sanitize_dom()` ## Default configuration Most of the issues above did **not** affect ordinary parsed HTML with the default `JustHTML(..., sanitize=True)` configuration. The main risk areas were: - custom policies that preserve SVG or MathML - custom policies that preserve `<style>` - programmatic DOM construction or mutation - low-level direct sanitizer/transform APIs ## Recommended action Upgrade to `justhtml` `1.17.0`. If users cannot upgrade immediately: - avoid preserving SVG or MathML for untrusted input - avoid preserving `<style>` for untrusted input - avoid mutating programmatic DOM trees with untrusted `script`, `style`, or comment content - avoid mutating warmed policy internals or sanitizer caches ## Credit Discovered during an internal security review of `justhtml`.

GHSA-vrx2-77f2-ww34

Date	Actor	Action	Vulnerability	Source	VulnerableCode Version
2026-06-13T06:29:33.337849+00:00	GHSA Importer	Fixing	VCID-pe3n-8tcx-5bb5	https://github.com/advisories/GHSA-vrx2-77f2-ww34	38.6.0
2026-06-12T22:25:11.547421+00:00	GitLab Importer	Affected by	VCID-ze6z-2zm7-rud9	https://gitlab.com/gitlab-org/advisories-community/-/blob/main/pypi/justhtml/GHSA-r8cj-3554-33mr.yml	38.6.0
2026-06-12T22:11:57.926489+00:00	GitLab Importer	Fixing	VCID-pe3n-8tcx-5bb5	https://gitlab.com/gitlab-org/advisories-community/-/blob/main/pypi/justhtml/GHSA-vrx2-77f2-ww34.yml	38.6.0
2026-06-12T07:45:40.061865+00:00	GithubOSV Importer	Fixing	VCID-pe3n-8tcx-5bb5	https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/04/GHSA-vrx2-77f2-ww34/GHSA-vrx2-77f2-ww34.json	38.6.0