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TI-2026-85117 Aliases CVE-2026-121971GHSA-wgw5-9p87-vhvp

Symfony HttpClient sends default scope credentials to other origins

Priority LOW 35CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
Present
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-200.

Summary

Symfony HttpClient in versions 5.x prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11 merges the default scope's options into a request before resolving a relative URL against the base URI. ScopingHttpClient keeps those options when a network-path reference such as //evil.example/steal leaves the base URI's origin, while the absolute form does not, which exposes the credentials (CWE-522). An unauthenticated remote attacker who controls the start of a URL passed to a client with a base_uri and credentials can receive those credentials.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Description from the CNA

The component ScopingHttpClient in Symfony HttpClient merges the options of its default scope (such as auth_bearer or auth_basic) into a request before resolving a relative URL against the base_uri, allowing a network-path reference such as "//evil.example/steal" to be sent to another origin together with the default scope’s credentials, and resulting in potential disclosure of those credentials to an attacker-controlled server. This affects Symfony in versions 5.x prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11. The resolved URL falls outside the origin of the base URI, yet it keeps the merged options, whereas the absolute spelling "https://evil.example/steal" receives none. The same happens with a different port or user-info part on the same host. This is reachable whenever an attacker controls the beginning of a URL passed to a client built with a base_uri and credentials, including those created with HttpClient::createForBaseUri() or configured under framework.http_client.scoped_clients. To solve the issue, after resolving a relative URL against the base URI of the default scope, ScopingHttpClient now compares the scheme and authority of the result with those of the base URI, parsed the way the request is sent.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00249 16th percentileScored 2026-11-07
Fix Fixed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

No affected products listed by the sources yet.

Remediation

Update Symfony to 5.4.56, 6.4.50, 7.4.23, or 8.1.11, the fixed version for each release line.

Written with Claude Haiku 5.5 from the sources below · 2026-11-06

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    sensiolabs symfony 5.4.56, 6.4.50 and 2 more versions

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-85040 Authentication bypass in Symfony X.509 authenticator via DN spoofingPriority LOW 35
    • TI-2026-85043 Symfony host placeholders bypass path-based access controlPriority LOW 28
    Show all 3 records →

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-11-04 Threatist record created from CVE-2026-121971
  2. 2026-11-04 Alias added: GHSA-wgw5-9p87-vhvp
  3. 2026-11-05 CISA SSVC decision points changed
  4. 2026-11-05 Priority changed: MEDIUM → LOW
  5. 2026-11-06 Affected versions changed · Red Hat
  6. 2026-11-06 CVSS score added · Red Hat

References

Patch 1

Advisory 1

  • TI-2019-13616 An issue was discovered in Symfony 3.4.0 through 3.4.34, 4.2.0 through 4.2.11, and 4.3.0… CVSS 3.1CRITICAL 9.8
  • TI-2018-10604 An issue was discovered in Http Foundation in Symfony 2.7.0 through 2.7.48, 2.8.0 through… CVSS 3.1MEDIUM 6.5
  • TI-2019-08131 In Symfony before 2.7.51, 2.8.x before 2.8.50, 3.x before 3.4.26, 4.x before 4.1.12, and… CVSS 3.1CRITICAL 9.8
  • TI-2016-02159 Symfony before 2.8.6 and 3.x before 3.0.6 allows remote attackers to bypass… CVSS 3.0CRITICAL 9.8
  • TI-2019-08459 An issue was discovered in Symfony before 4.2.12 and 4.3.x before 4.3.8. CVSS 3.1CRITICAL 9.8
  • TI-2018-08136 An issue was discovered in the Ldap component in Symfony 2.8.x before 2.8.37, 3.3.x… CVSS 3.0CRITICAL 9.8
See all 107 →

Sources

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