Description
A flaw was found in SSSD's PAM responder on builds with the JSON PAM extension enabled. A local attacker can submit a crafted authentication request containing a non-string OAuth2 code value. Missing JSON type validation leads to a NULL pointer dereference, terminating the PAM responder and disrupting SSSD-backed authentication.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
| 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 5 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | sssd | No fix yet | — |
| Ubuntu 26.04 LTS | sssd | No fix yet | — |
| Ubuntu 24.04 LTS | sssd | No fix yet | — |
| Ubuntu 22.04 LTS | sssd | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | sssd | No fix yet | — |
| Ubuntu Pro 18.04 LTS | sssd | No fix yet | — |
| Ubuntu Pro 16.04 LTS | sssd | No fix yet | — |
References
- https://access.redhat.com/security/cve/CVE-2026-127100 vdb-entry
- RHBZ#2572591 issue-tracking