CVE-2026-3904

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.

• CWE-366

• https://sourceware.org/bugzilla/show_bug.cgi?id=29863Exploit, Issue Tracking, Patch
• https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0004;hb=HEADThird Party Advisory
• https://sourceware.org/git/?p=glibc.git;a=commit;h=8804157ad9da39631703b92315460808eac86b0cPatch
• https://sourceware.org/git/?p=glibc.git;a=commit;h=b712be52645282c706a5faa038242504feb06db5Patch
• http://www.openwall.com/lists/oss-security/2026/03/11/5Mailing List, Third Party Advisory
• https://cert-portal.siemens.com/productcert/html/ssa-082556.html

Published

Mar 11, 2026

Last Modified

Jul 14, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
• Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
• PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
• AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.

• CVE-2026-38993Cockpit 2.13.5 and earlier is vulnerable to directory traver…6.5
• CVE-2026-39006An issue in SNMP4J-Agent 3.8.3 allows a remote attacker to e…9.8
• CVE-2026-39007An issue in Observeinc's Observe v.2026-01-28 and before all…7.5
• CVE-2026-3902An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.…7.5
• CVE-2026-3903The Modular DS: Monitor, update, and backup multiple website…4.3
• CVE-2026-39031Lansweeper lsrunase 2.0 and lsencrypt 2.0 use RC4 encryption…5.5
• CVE-2026-39042An issue in MikroTIk (SIA Mikrotikls, Latvia) RouterOS 7.21.…7.5
• CVE-2026-39047Buffer Overflow vulnerability in EPSON L14150 FL27PB allows …7.5
• CVE-2026-39052Oinone Pamirs 7.0.0 contains a code execution vulnerability …6.5
• CVE-2026-39053Oinone Pamirs 7.0.0 contains an XML External Entity (XXE) is…6.5
• CVE-2026-39054Oinone Pamirs 7.0.0 contains a command injection vulnerabili…7.3
• CVE-2026-3906WordPress core is vulnerable to unauthorized access in versi…4.3