# CVE-2026-123746: Symfony: Programmatic Logins Skip the checkPostAuth() Method of User Checkers

Status: published. Published: 2026-11-06. Updated: 2026-11-06.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: Checkmarx) — https://github.com/symfony/symfony/commit/af0aae5012beedf0a0c3fd581fd8b9ef696240c4

## Affected products and versions

- sensiolabs / symfony (symfony/security-http): ≥ 0; < 5.4.56 (affected, git); ≥ 6.0.0; < 6.4.50 (affected, git); ≥ 7.0.0; < 7.4.23 (affected, git); ≥ 8.0.0; < 8.1.11 (affected, git). Source: CNA: Checkmarx

## Severity and prioritization

- CVSS 4.0: 2.3 (low); CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N; source: CNA: Checkmarx

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-288

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/symfony/symfony/security/advisories/GHSA-8f57-m8wj-x65w (CNA: Checkmarx; third-party-advisory)

- https://github.com/symfony/symfony/commit/af0aae5012beedf0a0c3fd581fd8b9ef696240c4 (CNA: Checkmarx; patch)

## Provenance

- CNA: Checkmarx: https://www.cve.org/CVERecord?id=CVE-2026-123746; retrieved 2026-11-06; source updated 2026-11-06

Revision: b94fde01b52a5259703f72b66f26dc3196fbf0561c5b6da9f7f5c3c3b3354c0f

Canonical: https://y2.dev/cve/CVE-2026-123746

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