CVE-2016-2403: Symfony Authentication Bypass

critical Affects symfony/security, symfony/security-core, symfony/symfony. Feed 2026.10.29.1, updated 2026-10-28; published 2022-05-14; advisory modified 2024-02-16.

Symfony Authentication Bypass

Package: symfony/security Composer
Affected versions: >=2.8.0 and <2.8.6 or >=3.0.0 and <3.0.6
Fixed in: 2.8.6, 3.0.6
Severity: critical CVSS 9.8
Exploitation: not on CISA KEV · EPSS 4% (91.1th percentile)
Published: 2022-05-14
Source: osv.dev

References

Symfony Authentication Bypass

Package: symfony/security-core Composer
Affected versions: >=2.8.0 and <2.8.6 or >=3.0.0 and <3.0.6
Fixed in: 2.8.6, 3.0.6
Severity: critical CVSS 9.8
Exploitation: not on CISA KEV · EPSS 4% (91.1th percentile)
Published: 2022-05-14
Source: osv.dev

References

Symfony Authentication Bypass

Package: symfony/symfony Composer
Affected versions: >=2.8.0 and <2.8.6 or >=3.0.0 and <3.0.6
Fixed in: 2.8.6, 3.0.6
Severity: critical CVSS 9.8
Exploitation: not on CISA KEV · EPSS 4% (91.1th percentile)
Published: 2022-05-14
Source: osv.dev

References

CWE-287

NVD record symfony/security advisories symfony/security-core advisories symfony/symfony advisories

Am I affected?

Find out in one command. phpwarden checks your composer.lock against this advisory and 20,000+ others, ranked by real-world exploitation (CISA KEV + EPSS). Free, offline, open data.

# one-time install
pip install phpwarden

# then
phpwarden deps composer.lock

Or keep it checked automatically: GitHub Action · pre-commit hook · GitLab CI · Laravel artisan command

Install docs How findings are ranked

Related advisories

CVE-2015-8124 low Symfony Session Fixation Vulnerability same package: symfony/security
CVE-2015-8125 high Symfony Vulnerable to Timing Attack same package: symfony/security
CVE-2018-11407 critical Symfony Authentication Bypass same package: symfony/security
CVE-2018-11385 high Symfony Session Fixation Vulnerability same package: symfony/security
CVE-2016-1902 high Symfony Cryptographic Vulnerability same package: symfony/security
CVE-2012-6431 medium Symfony Allows URI Restrictions Bypass Via Double-Encoded String same package: symfony/security