UBUNTU-CVE-2026-48747
A vulnerability in the Symfony PHP framework prior to versions 7.4.13 and 8.0.13 allows a signature algorithm downgrade in the MailomatRequestParser::validateSignature() function. This occurs because the function parses the X-MOM-Webhook-Signature header and passes the request-selected algorithm to hash_hmac() instead of enforcing the documented SHA-256 algorithm. The issue is fixed in Symfony versions 7.4.13 and 8.0.13.
AI Analysis
Technical Summary
Symfony versions before 7.4.13 and 8.0.13 contain a vulnerability in the MailomatRequestParser::validateSignature() method. The method parses the X-MOM-Webhook-Signature header as algo=signature and uses the algorithm specified by the request in the hash_hmac() function. This allows an attacker to downgrade the signature algorithm from the intended SHA-256 to a weaker one, potentially bypassing signature verification. The vulnerability is resolved by enforcing the use of SHA-256 in the fixed versions 7.4.13 and 8.0.13.
Potential Impact
An attacker could exploit this vulnerability to downgrade the signature algorithm used for webhook signature verification, potentially allowing unauthorized requests to be accepted by the application. This undermines the integrity of webhook authentication, possibly leading to unauthorized actions or data exposure. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade Symfony to version 7.4.13 or 8.0.13 or later, where this vulnerability is fixed. No other mitigation is required as the fix enforces the correct signature algorithm.
UBUNTU-CVE-2026-48747
Description
A vulnerability in the Symfony PHP framework prior to versions 7.4.13 and 8.0.13 allows a signature algorithm downgrade in the MailomatRequestParser::validateSignature() function. This occurs because the function parses the X-MOM-Webhook-Signature header and passes the request-selected algorithm to hash_hmac() instead of enforcing the documented SHA-256 algorithm. The issue is fixed in Symfony versions 7.4.13 and 8.0.13.
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 versions before 7.4.13 and 8.0.13 contain a vulnerability in the MailomatRequestParser::validateSignature() method. The method parses the X-MOM-Webhook-Signature header as algo=signature and uses the algorithm specified by the request in the hash_hmac() function. This allows an attacker to downgrade the signature algorithm from the intended SHA-256 to a weaker one, potentially bypassing signature verification. The vulnerability is resolved by enforcing the use of SHA-256 in the fixed versions 7.4.13 and 8.0.13.
Potential Impact
An attacker could exploit this vulnerability to downgrade the signature algorithm used for webhook signature verification, potentially allowing unauthorized requests to be accepted by the application. This undermines the integrity of webhook authentication, possibly leading to unauthorized actions or data exposure. No known exploits in the wild have been reported.
Mitigation Recommendations
Upgrade Symfony to version 7.4.13 or 8.0.13 or later, where this vulnerability is fixed. No other mitigation is required as the fix enforces the correct signature algorithm.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-48747
- 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: 6a58b49a68715ace43da82c9
Added to database: 07/16/2026, 10:38:18 UTC
Last enriched: 07/16/2026, 12:27:38 UTC
Last updated: 07/16/2026, 12:27:38 UTC
Views: 2
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