Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-87853
Red Hat Red Hat Enterprise Linux 10 — Sssd: sssd: idp authentication prefix comparison allows cross-user impersonation
AV AC PR UI S C I A CVSS EPSS %ile KEV
N H L N U H H H 7.5 .0033 24.3 —
AFFECTED
Product Versions Fixed
Red Hat Enterprise Linux 10 unspecified 0:2.12.0-3.el10_2.2
Red Hat Enterprise Linux 6 unspecified —
Red Hat Enterprise Linux 7 unspecified —
Red Hat Enterprise Linux 8 unspecified —
Red Hat Enterprise Linux 9 unspecified —
Red Hat OpenShift Container Platform 4 unspecified —
Red Hat OpenShift Container Platform 4 unspecified —
TIMELINE
Sep 9 Reserved by redhat
Sep 9 Published (CNA: redhat)
Oct 8 PATCH SHIPPED — CVE-2026-87853 (Red Hat Enterprise Linux 10). Fixed in Red Hat Enterprise Linux 10 0:2.12.0-3.el10_2.2.
Description
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.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| September 9, 2026 | Reserved | Reserved by redhat |
| September 9, 2026 | Published | Published (CNA: redhat) |
| October 8, 2026 | PATCH SHIPPED | PATCH SHIPPED — CVE-2026-87853 (Red Hat Enterprise Linux 10). Fixed in Red Hat Enterprise Linux 10 0:2.12.0-3.el10_2.2. |
Affected
Affected products and packages — 7 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | 0:2.12.0-3.el10_2.2 |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | — |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | — |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | — |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | — |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-87853 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
