Sssd: sssd: denial of service in nss responder via crafted zero-length requests
Summary
| CVE | CVE-2026-90996 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-14 16:17:42 UTC |
| Updated | 2026-09-14 16:17:42 UTC |
| Description | A flaw was found in sssd. A local unprivileged user could send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder. This could lead to a denial-of-service condition, causing the NSS responder to become unstable or terminate. This vulnerability affects the availability of the system responder. |
Risk And Classification
Primary CVSS: v3.1 4 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Problem Types: CWE-191 | CWE-191 Integer Underflow (Wrap or Wraparound)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 4 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
| 3.1 | CNA | CVSS | 4 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L |
CVSS v3.1 Breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 6 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 7 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| CNA | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
| CNA | Red Hat | Red Hat OpenShift Container Platform 4 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| access.redhat.com/security/cve/CVE-2026-90996 | [email protected] | access.redhat.com | |
| bugzilla.redhat.com/show_bug.cgi | [email protected] | bugzilla.redhat.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: This issue was discovered by Found by AISLE in partnership with Red Hat. (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-05-18T03:32:25.000Z | Reported to Red Hat. |
| CNA | 2026-09-14T14:50:00.000Z | Made public. |
Workarounds
CNA: To mitigate this issue, restrict access to the NSS responder UNIX socket or disable the NSS responder if it is not required. The NSS responder can be disabled by editing the `/etc/sssd/sssd.conf` file and removing `nss` from the `services` line in the `[sssd]` section. After modifying the configuration, restart the SSSD service for the changes to take effect. Disabling the NSS responder may impact local user and group resolution. Example: ```bash # Remove 'nss' from the services line in /etc/sssd/sssd.conf # Before: services = nss, pam, autofs # After: services = pam, autofs sudo systemctl restart sssd ``` Warning: Restarting the `sssd` service will temporarily interrupt authentication and authorization services.