CVE-2026-104041: Sssd: sssd: denial of service via unbounded negative cache growth
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.1%
Up from <0.1% on .
EPSS score, percentile 3.1 of all scored records. A probability estimated by FIRST, not a report of exploitation.
CISA's SSVC assessment in the CVE record lists exploitation as poc.
- How severe?
- 5.5 Medium
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Workaround (from the CVE record)
Set `entry_negative_timeout = 0` in the `[nss]` section of `/etc/sssd/sssd.conf` to disable non-permanent negative-cache insertions, then restart the SSSD service (for example, `systemctl restart sssd`) to apply the change. Note that restarting sssd briefly interrupts active authentication and identity lookups, and disabling the negative cache increases lookup traffic to identity backends for nonexistent entries. If responder memory growth is observed, the accumulated negative-cache state can be cleared through the existing operational clear path or by restarting the responder. Restricting untrusted local users also limits exposure on systems where the NSS responder socket is reachable by local users.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|
Versions not listed are: affected.
| Status | Versions |
|---|
Versions not listed are: unknown.
| Status | Versions |
|---|
Versions not listed are: affected.
| Status | Versions |
|---|
Versions not listed are: affected.
| Status | Versions |
|---|
Versions not listed are: affected.
| Status | Versions |
|---|
Versions not listed are: affected.
| Status | Versions |
|---|
Versions not listed are: affected.
Source: CVE List, as of . About the data.
About this vulnerability
A flaw was found in SSSD. An unprivileged local user can repeatedly request lookups for nonexistent entries through the Name Service Switch (NSS) responder. Because the negative cache does not limit the total number of stored entries and only removes expired records when an existing key is rechecked, the cache can grow without bound. This behavior can lead to memory exhaustion, resulting in a Den…
Summary: CVE record, as of .
- CISA has not added CVE-2026-104041 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 6 Oct 2026.
- The CVE record carries a CVSS v3.1 base score of 5.5 (Medium), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.1% (percentile 3.1), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation poc, automatable no, technical impact partial.
- The credits in the CVE record name AISLE as finder.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
Sssd: sssd: denial of service via unbounded negative cache growth
A flaw was found in SSSD. An unprivileged local user can repeatedly request lookups for nonexistent entries through the Name Service Switch (NSS) responder. Because the negative cache does not limit the total number of stored entries and only removes expired records when an existing key is rechecked, the cache can grow without bound. This behavior can lead to memory exhaustion, resulting in a Denial of Service (DoS) as the responder becomes unresponsive or terminates.
Source: CVE List, as of . About the data.
Weakness
CWE-770
CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
References
2
Known exploited Red Hat vulnerabilities
- CVE-2015-3246: Red Hat Libuser Race Condition Vulnerability
- CVE-2015-5287: Red Hat Automatic Bug Reporting Tool Privilege Escalation Vulnerability
- CVE-2018-14667: Red Hat JBoss RichFaces Framework Expression Language Injection Vulnerability
- CVE-2021-3560: Red Hat Polkit Incorrect Authorization Vulnerability
- CVE-2021-4034: Red Hat Polkit Out-of-Bounds Read and Write Vulnerability