OSSA-2026-005: Restricted application credentials can create EC2 credentials

Date:

April 07, 2026

CVE:

CVE-2026-33551

Affects

• Keystone: >=14.0.0 <26.1.1, ==27.0.0, ==28.0.0, ==29.0.0

Description

Maxence Bornecque from Orange Cyberdefense CERT Vulnerability Intelligence Watch Team reported a vulnerability in Keystone’s EC2 credential creation endpoint. By using a restricted application credential to call the EC2 credential creation API, an authenticated user with only a reader role may obtain an EC2/S3 credential that carries the full set of the parent user’s S3 permissions, effectively bypassing the role restrictions imposed on the application credential. Only deployments that use restricted application credentials in combination with the EC2/S3 compatibility API (swift3 / s3api) are affected.

Patches

• https://review.opendev.org/983597 (2024.1/caracal)

• https://review.opendev.org/983591 (2024.2/dalmatian)

• https://review.opendev.org/983589 (2025.1/epoxy)

• https://review.opendev.org/983588 (2025.2/flamingo)

• https://review.opendev.org/983593 (2026.1/gazpacho)

• https://review.opendev.org/983587 (2026.2/hibiscus)

Credits

• Maxence Bornecque from Orange Cyberdefense CERT Vulnerability Intelligence Watch Team (CVE-2026-33551)

References

• https://launchpad.net/bugs/2142138

• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-33551

Notes

• The unmaintained/2024.1 branch is unmaintained and will receive no new point releases, but a patch for it is provided as a courtesy.