CVE-2026-3904
Description
A flaw was found in glibc. When calling NSS-backed functions that support caching via nscd, the nscd client under high load on x86_64 systems may call the memcmp function on inputs that are concurrently modified by other processes or threads, causing a crash and resulting in a denial of service.
Statement
This issue is only exploitable via applications using NSS-backed functions that support caching via nscd under a high load on x86_64 systems. It depends on a race condition on inputs that are concurrently modified by other processes or threads during memory access, increasing the complexity of exploitation. Also, this flaw can only cause an application crash, limiting the security impact to a denial of service. Due to these reasons, this vulnerability has been rated with a moderate severity.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.9 | N/A | 6.2 |
| Attack Vector | Network | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Alter Execution Logic; Unexpected State
The main problem is that -- if a lock is overcome -- data could be altered in a bad state.
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