DEBIAN-CVE-2026-87853

See a problem?
Please try reporting it to the source first.

Source

https://security-tracker.debian.org/tracker/CVE-2026-87853

Import Source

https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-87853.json

JSON Data

https://api.osv.dev/v1/vulns/DEBIAN-CVE-2026-87853

Upstream

CVE-2026-87853

Published

2026-09-09T17:17:52Z

Modified

2026-09-11T08:47:31Z

Severity

7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator

Summary

[none]

Details

A flaw was found in SSSD's IdP authentication provider. The eval_access_token_buf() function compares the OIDC subject identifier using strncmp() with the authenticated user's identifier length, performing a prefix comparison instead of an exact match. An attacker whose IdP identifier is a strict prefix of a target user's identifier can authenticate as the target user.

References

https://security-tracker.debian.org/tracker/CVE-2026-87853

Affected packages

Debian:12 / sssd

Package

Name: sssd
Purl: pkg:deb/debian/sssd?arch=source&distro=bookworm

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.8.2-4

2.8.2-4+deb12u1

2.9.1-1

2.9.1-2

2.9.2-1

2.9.4-1

2.9.4-1.1~exp1

2.9.4-1.1

2.9.4-2

2.9.5-1

2.9.5-2

2.9.5-3

2.9.5-4

2.9.5-5

2.10.1-1

2.10.1-2

2.11.1-1

2.11.1-2

2.11.1-2.1

2.12.0-1

2.12.0-2

2.12.0-3~exp0

2.12.0-4

2.13.1-1

2.13.1-2

2.13.1-3

Ecosystem specific

{
    "urgency": "not yet assigned"
}

Database specific

source

"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-87853.json"

Debian:13 / sssd