9.1

CVE-2026-45063: Symfony: Identity Spoofing via Unanchored DN Regex in X509Authenticator

Analyzed
AliasesUBUNTU-CVE-2026-45063DEBIAN-CVE-2026-45063
Published 14-07-2026Last modified 14-07-2026

Vulnerability summary

CVE-2026-45063 is a critical (CVSS 9.1) Authentication Bypass by Spoofing vulnerability in sensiolabs symfony. EPSS estimates a 0.37% chance of exploitation in the next 30 days, higher than 29.3% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.1/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.37%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Timeline

  1. 14-07-2026
    PublishedVulnerability first disclosed.
  2. 14-07-2026
    Last modifiedVulnerability information updated.

Description

Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Prior to 5.4.52, 6.4.40, 7.4.12, and 8.0.12, X509Authenticator extracts the user identifier from $_SERVER['SSL_CLIENT_S_DN'] with an unanchored regex that matches emailAddress= anywhere in the distinguished name, allowing an attacker with a trusted certificate containing emailAddress=victim inside another RDN value such as CN to authenticate as the victim. This issue is fixed in versions 5.4.52, 6.4.40, 7.4.12, and 8.0.12.

CVSS metrics

6 scores · 4 sources · 2 versions

EPSS trend

Probability

0.37%

Chance of exploitation in the next 30 days

Percentile

29%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.37% on 22-09-2026

22-09-202622-10-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • symfony< 5.4.53+dfsg-0+deb12u1 | < 6.4.41+dfsg-0+deb13u1 | < 7.4.12+dfsg-1
Sensiolabs1 product
  • symfony< 5.4.52 | ≥ 6.0.0, < 6.4.40 | ≥ 7.0.0, < 7.4.12 | ≥ 8.0.0, < 8.0.12
Symfony1 product
  • symfony< 5.4.52 | ≥ 6.0.0-BETA1, < 6.4.40 | ≥ 7.0.0-BETA1, < 7.4.12 | ≥ 8.0.0-BETA1, < 8.0.12
Ubuntu1 product
  • symfonyAll versions (No fix recorded)

4 vendors · 4 products

References

10 links