UBUNTU-CVE-2026-45066
A vulnerability in the Symfony PHP framework's HtmlSanitizer component allows off-allowlist URLs to bypass restrictions due to differences in URL parsing between the sanitizer and browsers, and incorrect policy checks for <area href> elements. This affects versions from 6.1.0-BETA1 up to but not including 6.4.40, 7.4.12, and 8.0.12, where the issue is fixed.
AI Analysis
Technical Summary
Symfony's HtmlSanitizer URL sanitization can allow URLs not on the allowlist to pass through when using allowLinkHosts() or allowMediaHosts(). This occurs because UrlSanitizer::parse() follows RFC 3986, whereas browsers follow WHATWG URL parsing, leading to discrepancies. Additionally, the <area href> attribute is checked against the media policy instead of the link policy, further enabling bypass. The vulnerability is fixed in Symfony versions 6.4.40, 7.4.12, and 8.0.12.
Potential Impact
The vulnerability may allow attackers to bypass URL allowlist restrictions in the HtmlSanitizer component, potentially enabling unsafe URLs to be accepted where only certain hosts should be allowed. This could lead to security issues related to unsafe content or links being rendered in applications using affected Symfony versions.
Mitigation Recommendations
A fix is available in Symfony versions 6.4.40, 7.4.12, and 8.0.12. Users should upgrade to these or later versions to remediate the vulnerability. No vendor advisory content was provided to indicate alternative mitigations or that no action is required.
UBUNTU-CVE-2026-45066
Description
A vulnerability in the Symfony PHP framework's HtmlSanitizer component allows off-allowlist URLs to bypass restrictions due to differences in URL parsing between the sanitizer and browsers, and incorrect policy checks for <area href> elements. This affects versions from 6.1.0-BETA1 up to but not including 6.4.40, 7.4.12, and 8.0.12, where the issue is fixed.
CVSS v4.0
Affected software
pkg:deb/ubuntu/[email protected]?arch=source&distro=xenialpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu0.1+esm2?arch=source&distro=esm-apps/bionicpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu1+esm2?arch=source&distro=esm-apps/focalpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu8+esm1?arch=source&distro=esm-apps/jammypkg:deb/ubuntu/[email protected]+dfsg-3ubuntu3+esm1?arch=source&distro=esm-apps/noblepkg:deb/ubuntu/[email protected]+dfsg-1?arch=source&distro=questingpkg:deb/ubuntu/[email protected]+dfsg-1ubuntu1?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Symfony's HtmlSanitizer URL sanitization can allow URLs not on the allowlist to pass through when using allowLinkHosts() or allowMediaHosts(). This occurs because UrlSanitizer::parse() follows RFC 3986, whereas browsers follow WHATWG URL parsing, leading to discrepancies. Additionally, the <area href> attribute is checked against the media policy instead of the link policy, further enabling bypass. The vulnerability is fixed in Symfony versions 6.4.40, 7.4.12, and 8.0.12.
Potential Impact
The vulnerability may allow attackers to bypass URL allowlist restrictions in the HtmlSanitizer component, potentially enabling unsafe URLs to be accepted where only certain hosts should be allowed. This could lead to security issues related to unsafe content or links being rendered in applications using affected Symfony versions.
Mitigation Recommendations
A fix is available in Symfony versions 6.4.40, 7.4.12, and 8.0.12. Users should upgrade to these or later versions to remediate the vulnerability. No vendor advisory content was provided to indicate alternative mitigations or that no action is required.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-45066
- Osv Schema Version
- 1.7.0
- Aliases
- []
- Ecosystems
- ["Ubuntu:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:Pro:22.04:LTS","Ubuntu:Pro:24.04:LTS","Ubuntu:25.10","Ubuntu:26.04:LTS"]
- Database Specific Severity
- null
- Cvss Version
- 4.0
Threat ID: 6a58b4b168715ace43da95c3
Added to database: 07/16/2026, 10:38:41 UTC
Last enriched: 07/16/2026, 12:49:38 UTC
Last updated: 07/16/2026, 12:49:38 UTC
Views: 2
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