GHSA-j8gj-9rm5-4xhx CVE-2026-45074
Symfony's Cas2Handler Derives CAS service URL from Client Host Header → Cross-Service Ticket Replay
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.49%
- Chance of exploitation in the next 30 days. Higher than 42.06% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-290 Authentication Bypass by Spoofing
- Fix
- Available
- 2 packages have a fixed version
Description
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 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.
Affected versions
Packagist
| Package | Vulnerable | Fixed in |
|---|---|---|
| symfony/security-http | >= 7.1.0, < 7.4.12 |
7.4.12 |
| symfony/security-http | >= 8.0.0, < 8.0.12 |
8.0.12 |
| symfony/symfony | >= 7.1.0, < 7.4.12 |
7.4.12 |
| symfony/symfony | >= 8.0.0, < 8.0.12 |
8.0.12 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
symfony/security-http Packagist → 7.4.12
- composer
composer require symfony/security-http:^7.4.12
symfony/symfony Packagist → 7.4.12
- composer
composer require symfony/symfony:^7.4.12
Severity breakdown
CVSS 4.0 0.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- High
- Availability (vulnerable system)
- None
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Unreported
CVSS 3.1 8.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Weakness
CWE-290: Authentication Bypass by Spoofing
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.
References
Packages
Other links
- github.com/symfony/symfony/security/advisories/GHSA-j8gj-9rm5-4xhx
- github.com/symfony/symfony/commit/5ba145dba702404801bdf9e7e8d6df170060d541
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/C…
- github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-202…
- symfony.com/cve-2026-45074
- github.com/symfony/symfony/releases/tag/v7.4.12
- github.com/symfony/symfony/releases/tag/v8.0.12
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-2v3c-qxhr-7vpv Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process | High | Also affects symfony/symfony |
| GHSA-r925-mgvr-h9cc Symfony: ReDoS in HeaderUtils::split() Reachable Through the Cache-Control Request Header | High | Also affects symfony/symfony |
| GHSA-h5x3-xfc9-m39h Symfony: UrlGenerator Dot-Segment Encoding Skips Every Other Chained `../` or `./` → Generated URL Collapses Off-Route Under RFC 3986 Normalization | Medium | Also affects symfony/symfony |
| GHSA-v3wm-qf9p-c549 Symfony: HtmlSanitizer URL Parser Deny Gates Underinclusive: Percent-Encoded BiDi Marks and Unicode Whitespace Bypass Visual-Spoofing Defense | Medium | Also affects symfony/symfony |
| GHSA-rrj9-5q2j-4gvr Symfony: Mailomat Mailer Webhook Parser Reads the HMAC Algorithm from the Request: Signature Algorithm Downgrade | Medium | Also affects symfony/symfony |
| GHSA-38cx-cq6f-5755 Symfony: IpUtils::PRIVATE_SUBNETS Omits IPv6 Transition Forms (6to4, NAT64, Teredo, IPv4-compatible): SSRF Bypass in NoPrivateNetworkHttpClient | High | Also affects symfony/symfony |
| GHSA-6h46-9jf5-q59x Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes | High | Also affects symfony/security-http |
| GHSA-x5qj-865h-mgvm Symfony: HtmlSanitizer UrlAttributeSanitizer Misses URL Attributes | Medium | Also affects symfony/symfony |
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