CVE-2026-127099
Sssd: sssd: stack buffer overflow during rsa certificate-to-ssh key conversion
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
What each source reports
CVE List Score used
Sssd: sssd: stack buffer overflow during rsa certificate-to-ssh key conversion
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.
- Record
CVE-2026-127099- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-121
- Updated
- 2026-11-12
EUVDEUVD-2026-124599
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.
- Record
EUVD-2026-124599- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Updated
- 2026-11-12
GitHub AdvisoriesGHSA-66mh-fp5j-jphj
A flaw was found in SSSD's conversion of X.509 certificate RSA public keys to SSH keys. Missing...
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.
- Record
GHSA-66mh-fp5j-jphj- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-121
- Updated
- 2026-11-12
NVD
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.
- Record
CVE-2026-127099- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-121
- Updated
- 2026-11-12
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| published | EUVD | |
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-127099 is a medium vulnerability (CVSS 5.9) in Red Hat Enterprise Linux 10, published November 12, 2026. No source lists public exploit code. No source names a fixed version.