Improper Verification of Cryptographic Signature in Symfony - CVE-2026-48747
Published: June 1, 2026
Vulnerability identifier: #VU133117
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-48747
CWE-ID: CWE-347
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to compromise the target system.
The vulnerability exists due to improper verification of a cryptographic signature in the Mailomat webhook parser. A remote attacker can specify the HMAC algorithm and downgrade the cryptographic protection on the system.
Affected software
Symfony
How to mitigate CVE-2026-48747
Install updates from vendor's website.
Symfony - addressed in versions 7.4.13, 8.0.13