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.
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.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| The GNU C Library | glibc | unaffected |
|
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Project Subscriptions
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Advisories
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Fixes
Solution
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Workaround
No workaround given by the vendor.
References
History
Wed, 11 Mar 2026 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Weaknesses | CWE-366 | |
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: glibc
Published:
Updated: 2026-03-11T13:19:09.741Z
Reserved: 2026-03-10T19:52:49.054Z
Link: CVE-2026-3904
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-03-11T14:16:30.113
Modified: 2026-03-11T14:16:30.113
Link: CVE-2026-3904
Redhat
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OpenCVE Enrichment
No data.
Weaknesses