VulnerabilityPublished 14 Sep 2026Updated 7 Oct 2026

CVE-2026-90996: Red Hat Enterprise Linux 10 · Integer Underflow

Affects Red Hat Enterprise Linux 10Source CVE Database V5

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Not known to be exploited · CVSS 4.0 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

4.0Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 14 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Red Hat Enterprise Linux 10sssd	Affected–	Fixed in–
Red Hat Enterprise Linux 6sssd	Affected–	Fixed in–
Red Hat Enterprise Linux 7sssd	Affected–	Fixed in–
Red Hat Enterprise Linux 8sssd	Affected–	Fixed in–
Red Hat Enterprise Linux 9sssd	Affected–	Fixed in–
Red Hat OpenShift Container Platform 4openshift/ose-rhel-coreos-8	Affected–	Fixed in–

AI-suggested

Until a fix is confirmed, consider restricting local unprivileged user access or monitoring for unusual NSS responder behavior to mitigate potential denial-of-service conditions.

Description

CVE-2026-90996 is an integer underflow vulnerability in the sssd component of Red Hat Enterprise Linux 10. A local unprivileged user can send a specially crafted request with a zero-length body to the Network Security Services (NSS) responder, potentially causing it to become unstable or terminate. This results in a denial-of-service condition affecting system availability. The vulnerability has a medium severity rating with a CVSS score of 4. No specific affected versions or patch information are provided in the available data.

Impact

The primary impact is a denial-of-service condition that affects the availability of the NSS responder on Red Hat Enterprise Linux 10 systems. This could disrupt authentication or other services relying on NSS, but there is no impact on confidentiality or integrity according to the CVSS vector.

Summary

This vulnerability involves an integer underflow (wrap or wraparound) in the sssd component of Red Hat Enterprise Linux 10. An unprivileged local user can exploit this by sending a specially crafted request with a zero-length body to the NSS responder, leading to a denial-of-service condition by causing the NSS responder to become unstable or terminate. The issue impacts the availability of the NSS responder service but does not affect confidentiality or integrity.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Oct 2026, 19:12 UTC

Technical details

References

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