Apache CXF vulnerability

Apache CXF’s OIDC relying-party component could redirect users to an attacker-controlled URL after successful authentication. The issue occurs because attacker-controlled state parameters are preserved and later used as redirect targets without validating that the final decoded URI belongs to the RP’s origin. Both directly encoded and double-encoded external URLs can trigger the issue, depending on which validation path is used. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Published 9 Oct 2026Updated 20 Oct 20262 sources
CVSS 6.1

What happened

Apache CXF’s OIDC relying-party component could redirect users to an attacker-controlled URL after successful authentication. The issue occurs because attacker-controlled state parameters are preserved and later used as redirect targets without validating that the final decoded URI belongs to the RP’s origin. Both directly encoded and double-encoded external URLs can trigger the issue, depending on which validation path is used. Users are recommended to upgrade to versions 4.2.4 or 4.1.9 or 3.6.13, which fix this issue.

Affected versions

Apache CXF: 4.2.0 through before 4.2.4 (semver); 4.0.0 through before 4.1.9 (semver); before 3.6.13 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.