Symfony: Programmatic Logins Skip the checkPostAuth() Method of User Checkers

Description

The Symfony Security HTTP component AuthenticatorManager::authenticateUser() does not run the firewall user checker’s checkPostAuth() method when a user is authenticated programmatically, allowing an account rejected by a custom user checker, such as an expired account, to be authenticated in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. AuthenticatorManager::authenticateUser() is used by UserAuthenticatorInterface::authenticateUser() and by the SecurityBundle’s Security::login() to authenticate a user programmatically, but it does not dispatch the security.authentication.success event, on which checkPostAuth() runs. The fix for CVE-2024-50341 made Security::login() call checkPreAuth(), but checkPostAuth() was still skipped. As a result, an account rejected by a custom user checker in checkPostAuth() is refused by form login and the other authenticators of the firewall, but can still be authenticated programmatically. Applications are affected when they use a custom user checker that rejects users in checkPostAuth() and authenticate users programmatically, for example after a password reset or an e-mail verification link. A user whose account is rejected can then obtain an authenticated session through that flow. The default user checker does nothing in checkPostAuth(), so the default configuration is not affected. The fix makes AuthenticatorManager::authenticateUser() dispatch the security.authentication.success event once the token is created and before it is stored, as authentications through the firewall do, so that checkPostAuth() runs and can reject the user.

Timeline

Scores

EPSS (exploitation in 30 days)

0.28% · top 80% of all CVEs (8 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Low 2.3.

Weakness

• CWE-288 Authentication bypass using an alternate path or channel (opens in a new tab)All about CWE-288 and its CVEs

Affected products

• sensiolabs · symfony

  • affected < 5.4.56
  • affected 6.0.0 – < 6.4.50
  • affected 7.0.0 – < 7.4.23
  • affected 8.0.0 – < 8.1.11

References (2)

• https://github.com/symfony/symfony/security/advisories/GHSA-8f57-m8wj-x65w (opens in a new tab)third-party-advisory
• https://github.com/symfony/symfony/commit/af0aae5012beedf0a0c3fd581fd8b9ef696240c4 (opens in a new tab)patch

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-123746](https://cveledger.app/badge/CVE-2026-123746.svg)](https://cveledger.app/cve/CVE-2026-123746)

Record last updated 6 Nov 2026, 12:36 UTC.