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CVE-2026-127099

Sssd: sssd: stack buffer overflow during rsa certificate-to-ssh key conversion

  • Medium 5.9

Description

A flaw was found in SSSD's conversion of X.509 certificate RSA public keys to SSH keys. Missing size checks before copying RSA components into fixed-size stack buffers can cause a stack buffer overflow. An attacker able to supply a certificate with oversized RSA components that passes the configured certificate checks can cause denial of service and corrupt SSH responder memory.

Key facts

Published
12 Nov 2026
Last changed
12 Nov 2026
Assigned by
redhat
EPSS
0.169% likely to be exploited in the next 30 days, higher than 6.344% of CVEs (scores for 15 Nov 2026)
SSVC (CISA)
Exploitation: none; Automatable: no; Technical impact: partial

Severity scores

Each score is shown as its source gave it. They are not averaged or merged.

  • 5.9CVSS 3.1, Mediumfrom the CNA (redhat)CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

What to do

  • Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.CNA workaround statement

Historical context and remediation

This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.

No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.

Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.

Read the original CVE record.

Affected products

VendorProductVersions
Red HatRed Hat Enterprise Linux 10
  • Default status: affected
Red HatRed Hat Enterprise Linux 6
  • Default status: affected
Red HatRed Hat Enterprise Linux 7
  • Default status: affected
Red HatRed Hat Enterprise Linux 8
  • Default status: affected
Red HatRed Hat Enterprise Linux 9
  • Default status: affected
Red HatRed Hat OpenShift Container Platform 4
  • Default status: affected
Red HatRed Hat OpenShift Container Platform 4
  • Default status: affected
Red HatRed Hat OpenShift Container Platform 5
  • Default status: affected

Timeline

  1. 15 Oct 2026 Reported to Red Hat.
  2. 12 Nov 2026 Made public.
  3. 12 Nov 2026 Published

Weakness

References