OSSA-2026-042: Zaqar empty URL-Signature header bypasses authentication

Date:

September 24, 2026

CVE:

CVE-2026-97404

Affects

  • Zaqar: >=1.0.0 <20.1.2, >=21.0.0 <21.0.2, >=22.0.0 <22.0.2

Description

pple, an independent security researcher, reported that Zaqar’s WSGI transport mishandles an empty URL-Signature header: a request carrying the header with an empty value bypasses both Keystone authentication and pre-signed URL verification. An unauthenticated remote attacker who knows a target project’s UUID can then read, enumerate, create, and delete that project’s queues, messages, claims, and subscriptions. By additionally claiming an administrative role, the attacker may also perform administrative operations, such as managing pools and flavors in admin_mode deployments. Only deployments using the WSGI transport with an authentication strategy configured are affected; the websocket transport is not affected.

Patches

Credits

  • pple from Independent (CVE-2026-97404)

References

Notes

  • This issue is distinct from the EXTRA-SPEC header bypass in OSSA-2026-029; the fix for that issue removed the EXTRA-SPEC branch but left the empty-value handling of the URL-Signature header untouched.