CVE-2026-127099

MEDIUMCVSS 5.9/10

Last modified

CVE-2026-127099 is a medium-severity vulnerability rated 5.9/10 on the CVSS scale. 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.

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.

Metrics

Weakness Enumeration

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
Red HatRed Hat Enterprise Linux 10All versions
Red HatRed Hat Enterprise Linux 6All versions
Red HatRed Hat Enterprise Linux 7All versions
Red HatRed Hat Enterprise Linux 8All versions
Red HatRed Hat Enterprise Linux 9All versions
Red HatRed Hat OpenShift Container Platform 4All versions
Red HatRed Hat OpenShift Container Platform 5All versions

References

Timeline

Published
Last Modified
Status
Awaiting Analysis

Frequently Asked Questions

What is CVE-2026-127099?
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.
How severe is CVE-2026-127099?
CVE-2026-127099 has a CVSS score of 5.9/10 (MEDIUM severity).
How do I fix CVE-2026-127099?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST