CVE-2026-3904

MEDIUM EPSS 4.2%
Published Mar 11, 20263mo ago · Modified Jun 17, 20262w ago
6.2 CVSS 3.1
Medium
Find Similar
Published Mar 11, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

Description

Calling NSS-backed functions that support caching via nscd may call the nscd client side code and in the GNU C Library version 2.36 under high load on x86_64 systems, the client may call memcmp on inputs that are concurrently modified by other processes or threads and crash. The nscd client in the GNU C Library uses the memcmp function with inputs that may be concurrently modified by another thread, potentially resulting in spurious cache misses, which in itself is not a security issue.  However in the GNU C Library version 2.36 an optimized implementation of memcmp was introduced for x86_64 which could crash when invoked with such undefined behaviour, turning this into a potential crash of the nscd client and the application that uses it. This implementation was backported to the 2.35 branch, making the nscd client in that branch vulnerable as well.  Subsequently, the fix for this issue was backported to all vulnerable branches in the GNU C Library repository. It is advised that distributions that may have cherry-picked the memcpy SSE2 optimization in their copy of the GNU C Library, also apply the fix to avoid the potential crash in the nscd client.

CVSS Details

Base Score
6.2
Exploitability
2.5
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
4.2% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-366

Affected Products 1

VendorProductVersionRange
gnuglibc*≥2.35  –  <2.37

References 5

  • openwall.com http://www.openwall.com/lists/oss-security/2026/03/11/5
    Mailing ListThird Party Advisory
  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=29863
    ExploitIssue TrackingPatch
  • sourceware.org https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0004;hb=HEAD
    Third Party Advisory
  • sourceware.org https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0c
    Patch
  • sourceware.org https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5
    Patch

Remediation

  • sourceware.org https://sourceware.org/bugzilla/show_bug.cgi?id=29863
    ExploitIssue TrackingPatch
  • sourceware.org https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0c
    Patch
  • sourceware.org https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5
    Patch