CVE-2026-45063Network attack vector

Identity spoofing via unanchored DN regex

Published Jul 14, 2026 · Updated Jul 14, 2026

Authentication bypass in Symfony before 5.4.52, 6.4.40, 7.4.12, and 8.0.12 allows remote attackers to authenticate as another user. X509Authenticator applies an unanchored regex to SSL_CLIENT_S_DN and accepts emailAddress= text embedded inside another RDN value as the user identifier. Exploitation requires an application using this mTLS authenticator and a certificate from its trusted CA whose free-text subject field can contain the victim identifier.

CVSS severity9.1
Critical
EPSS probability0.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Symfony before 5.4.52, 6.4.40, 7.4.12, and 8.0.12 allows remote attackers to authenticate as another user. X509Authenticator applies an unanchored regex to SSL_CLIENT_S_DN and accepts emailAddress= text embedded inside another RDN value as the user identifier. Exploitation requires an application using this mTLS authenticator and a certificate from its trusted CA whose free-text subject field can contain the victim identifier.

The record

CVE
CVE-2026-45063
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Symfony
Product
Symfony
Classifications
CWE-290
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 5.4.52
  2. Affected versionversion=>= 6.0.0-BETA1, < 6.4.40
  3. Affected versionversion=>= 7.0.0-BETA1, < 7.4.12
  4. Affected versionversion=>= 8.0.0-BETA1, < 8.0.12

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Symfony · Symfonyversion=< 5.4.52; version=>= 6.0.0-BETA1, < 6.4.40; version=>= 7.0.0-BETA1, < 7.4.12; version=>= 8.0.0-BETA1, < 8.0.12

Published CVSS scores

8.7GitHub Advisory DatabaseCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
9.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
9.1GitHub, Inc.CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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