CVE catalog

CVE-2026-87853

A flaw was found in SSSD's IdP authentication…

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.

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
Published: Sep 9, 2026, 2:15:45 PM UTC
Updated: Sep 9, 2026, 5:17:52 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.33% · Oct 27, 2026

Projects and upstream resources

[sssd][Source-reported homepage]

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence

Original provider fields

{
  "package_releases": [
    {
      "name": "sssd",
      "status": "vulnerable",
      "release": "sid",
      "version": "2.13.1-3"
    },
    {
      "name": "sssd",
      "status": "vulnerable",
      "release": "trixie",
      "version": "2.10.1-2"
    },
    {
      "name": "sssd",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "2.8.2-4+deb12u1"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1147731,
      "name": "sssd",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1147731,
      "name": "sssd",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1147731,
      "name": "sssd",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": [
    {
      "name": "sssd",
      "distro": "opensuse",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.13.1-3.1"
            }
          ]
        }
      ],
      "release": "tumbleweed",
      "versions": [],
      "ecosystem": "rpm",
      "fixed_version": "2.13.1-3.1",
      "provider_record_id": "OPENSUSE-SU-2026:11825-1"
    }
  ]
}

[Debian bug #1147731]

Publisher notes

[trixie] sssd: Minor issue

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[libipa-hbac0]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libipa-hbac-dev]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libnss-sss]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libpam-sss]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-certmap0]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-certmap-dev]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-idmap0]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-idmap-dev]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-nss-idmap0]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-nss-idmap-dev]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-simpleifp0]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-simpleifp-dev]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[libsss-sudo]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[python3-libipa-hbac]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[python3-libsss-nss-idmap]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[python3-sss]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[sssd]Unknown
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[sssd-ad]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[sssd-ad-common]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
[sssd-common]Unknown
Source package: [sssd]
Details (2)
- 2.8.2-4+deb12u1 · amd64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12
- 2.8.2-4+deb12u1 · arm64 · bookworm
  Affected
  nvd · sssd · debian · bookworm; nvd · sssd · debian · 12

Next results

Observed: Oct 23, 2026, 9:28:28 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]