Symfony Security: Programmatic Logins Skip checkPostAuth() User Checks

Published as "Programmatic Logins Skip the checkPostAuth() Method of User Checkers"

low Symfony Symfony components · Last reviewed Nov 10, 2026

CVE: CVE-2026-123746
GHSA: None
Packagist: PKSA-jvjt-tspc-256s
Reported: Nov 4, 2026

Lets accounts a user checker rejects in checkPostAuth(), such as expired ones, log in through Security::login() or authenticateUser().

Affected and fixed versions

In 2 packages: symfony/security-http and symfony/symfony. Find the row for the version you run, and update to the release next to it.

If you run	Update to	Support
8.1.0 – 8.1.10	8.1.11	Supported
7.4.0 – 7.4.22	7.4.23	Supported
6.4.0 – 6.4.49	6.4.50	Supported
5.4.0 – 5.4.55	5.4.56	Supported

Show 11 older branches, no longer supported

8.0.0 – 8.0.x	8.1.11
7.0.0 – 7.0.x	7.4.23
7.1.0 – 7.1.x	7.4.23
7.2.0 – 7.2.x	7.4.23
7.3.0 – 7.3.x	7.4.23
6.0.0 – 6.0.x	6.4.50
6.1.0 – 6.1.x	6.4.50
6.2.0 – 6.2.x	6.4.50
6.3.0 – 6.3.x	6.4.50
5.2.2 – 5.2.x	5.4.56
5.3.0 – 5.3.x	5.4.56

Upgrade

Run the line for the branch you are on. 1 other package listed above is affected too; update it the same way.

composer require symfony/security-http:^8.1.11
composer require symfony/security-http:^7.4.23
composer require symfony/security-http:^6.4.50
composer require symfony/security-http:^5.4.56

What this means

When a Symfony app logs a user in from code, through Security::login() or UserAuthenticatorInterface::authenticateUser(), the checkPostAuth() method of the firewall's user checker never ran. An account your user checker rejects there, such as an expired one, could still be logged in this way, even though form login refuses it.

Apps often log users in from code after a password reset or an email verification link. See the Symfony advisory and the fix.

Who is affected

Your app is exposed when both of these are true:

It has a custom user checker (a class implementing UserCheckerInterface) that rejects users in checkPostAuth().
It logs users in with Security::login() or authenticateUser().

On 6.4 and later, Symfony's default user checker does nothing in checkPostAuth(), so apps without a custom checker aren't affected. On 5.4, the default checker rejects users of the deprecated User class whose credentials expired, so those apps are affected too.

What to do

Update symfony/security-http (or symfony/symfony) to 5.4.56, 6.4.50, 7.4.23 or 8.1.11, depending on your branch.

After the update, an exception thrown by checkPostAuth() comes out of Security::login() and authenticateUser(). Code that logs users in from a controller, such as a registration controller, may need to catch it. authenticateUser() still skips checkPreAuth() on purpose, so checks like "email not verified yet" don't block freshly registered users.

Reported by Vincent Cassiau (CyberVanguard).

Check your app with an agent

Paste this into a coding agent that can read your project, such as Claude Code, Codex or Amp. It checks your composer.lock against the versions above and tells you what to update, without changing anything.

Check whether the PHP project you have access to is affected by this security advisory, and tell me what to update. Do a read-only check: don't edit files, don't run composer update or composer require, and don't try to reproduce the flaw.

Advisory: Symfony Security: Programmatic Logins Skip checkPostAuth() User Checks (CVE-2026-123746)
Details: https://phpnews.net/security/symfony/pksa-ct6b-k8d9-m631

Affected versions, as Composer constraints:
- symfony/security-http, symfony/symfony: >=5.2.2,<5.3.0|>=5.3.0,<5.4.0|>=5.4.0,<5.4.56|>=6.0.0,<6.1.0|>=6.1.0,<6.2.0|>=6.2.0,<6.3.0|>=6.3.0,<6.4.0|>=6.4.0,<6.4.50|>=7.0.0,<7.1.0|>=7.1.0,<7.2.0|>=7.2.0,<7.3.0|>=7.3.0,<7.4.0|>=7.4.0,<7.4.23|>=8.0.0,<8.1.0|>=8.1.0,<8.1.11

Fixed releases on branches that still get security fixes:
- 8.1.0 – 8.1.10: update to 8.1.11
- 7.4.0 – 7.4.22: update to 7.4.23
- 6.4.0 – 6.4.49: update to 6.4.50
- 5.4.0 – 5.4.55: update to 5.4.56

1. Find every composer.lock in the project outside vendor/ (a monorepo can have one per app) and read the installed version of each package above. Packages installed as dependencies of other packages count too.
2. Compare each installed version with its constraint: "|" separates alternative ranges, and "," means both bounds apply.
3. For each affected install, read "What this means" at https://phpnews.net/security/symfony/pksa-ct6b-k8d9-m631 and check whether the project meets the conditions it describes (a feature in use, a config value, a driver). Say which conditions you could check and which you couldn't.
4. Report a table: lock file | package | installed version | affected (yes, no or unknown) | conditions met (yes, no or unknown) | update to | evidence. For each affected package, give the command that would fix it, without running it: composer update <package> --with-dependencies when it is only installed as a dependency of another package, or composer require with the fixed version when composer.json requires it directly. If the installed version is on a branch with no fixed release listed, say it needs a move to a newer branch.

Sources

← All Symfony advisories