Skip to main content

Boteraser | Website and Server Security Solutions

🛡️ CVE-2026-45074 — symfony

🟠 CVSS 8.1 — High ✅ No Known Exploit CWE-290 NVD
8.1
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Symfony's Cas2Handler Derives CAS service URL from Client Host Header → Cross-Service Ticket Replay

Cas2Handler builds this service parameter from Request::getSchemeAndHttpHost(), which reflects the attacker-controlled HTTP Host header whenever Symfony's framework.trusted_hosts setting is not configured (the default). An attacker who controls any *other* application registered with the same CAS server can replay a victim's ticket against the Symfony application, with a spoofed Host header, and be authenticated as that victim.

Resolution

A new required service_url configuration option is introduced on Cas2Handler. The CAS service parameter sent to the validation endpoint is now built from this configured URL instead of being derived from the request's Host header, preventing cross-service ticket replay via Host header spoofing.

The patch for this issue is available [here](https://github.com/symfony/symfony/commit/5ba145dba702404801bdf9e7e8d6df170060d541) for branch 7.4.

Credits

Symfony would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and Nicolas Grekas for providing the fix.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: Required — someone has to click, open or visit something.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: None.

Weakness class

CVE-2026-45074 is classified as CWE-290: Authentication Bypass by Spoofing. Identity is inferred from something an attacker can forge, such as a header or address.

Affected software

CVE-2026-45074 is recorded against 3 packages.

  • symfony (from 8.0.0 up to 8.0.12)
  • symfony/security-http (from 8.0.0 up to 8.0.12)
  • symfony/symfony (from 8.0.0 up to 8.0.12)

Timeline and source

Published on 14 July 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.

References

github.com
github.com
github.com
github.com

Other advisories for this package

symfony has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-290: Authentication Bypass by Spoofing) in other software:

CVE-2026-45074 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Details

Severity HIGH
CVSS Score 8.1
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CWE CWE-290
Public Exploit ✅ No
Source NVD
Published 2026-07-14
Updated 2026-08-20
Modified 2026-07-15

Affected Packages

Software From version Fixed in
symfony 8.0.0 8.0.12
symfony/security-http 8.0.0 8.0.12
symfony/symfony 8.0.0 8.0.12

Similar Threats

Site Security Check

Is symfony part of your stack?

CVE-2026-45074 is rated CVSS 8.1 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.

Scan My Site Free →

No credit card required  ·  Results in minutes

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

Browse related advisories

All advisoriesCVECVE 2026
✓