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NVD / CVE Program· CNA glibc

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 h

Noroxi assessment

Priority: Monitor (action score 24/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.15% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: glibc (Debian:12) 2.36-9; glibc (Red Hat:hummingbird:1) 0:2.42-11.1.hum1; glibc-all-langpacks (Red Hat:hummingbird:1) 0:2.42-11.1.hum1.

Low priority for now. Upgrade to glibc (Debian:12) 2.36-9; glibc (Red Hat:hummingbird:1) 0:2.42-11.1.hum1; glibc-all-langpacks (Red Hat:hummingbird:1) 0:2.42-11.1.hum1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

MediumCVSS 6.2 · v3.1—No exploit Fix available
Published
Mar 11, 2026
Updated
Oct 15, 2026
EPSS
0.1% · 4th percentile

Report tools

JSON

Action score

24

Monitor

Low priority for now.

CVSS
24 / 40 · 6.2 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-3904

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
gnuglibc

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • gnu glibc2.35 and later · before 2.37

Versions reported by the vendor

Affected version ranges reported by the assigning authority (glibc). Independent of NVD's CPE analysis and usually ahead of it.

  • The GNU C Library glibc

    • 2.35 and later · before 2.37affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12glibcbefore 2.36-92.36-9
Red Hat:hummingbird:1glibcbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-all-langpacksbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-benchtestsbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-commonbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-develbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-docbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-gconv-extrabefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-aabefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-afbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-agrbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-akbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-ambefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-anbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-anpbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-arbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-asbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-astbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-aycbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-azbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-bebefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-bembefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-berbefore 0:2.42-11.1.hum10:2.42-11.1.hum1
Red Hat:hummingbird:1glibc-langpack-bgbefore 0:2.42-11.1.hum10:2.42-11.1.hum1

+96

Same product

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Published before and after this one in the same product

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    30Monitor
  • ← EarlierCVE-2025-15281Jan 20, 2026 · wordexp with WRDE_REUSE and WRDE_APPEND may return uninitialized memory
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  • Later →CVE-2026-4437Mar 20, 2026 · gethostbyaddr and gethostbyaddr_r may incorrectly handle DNS response
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:glibc2.36-9 · Debian:12Package registry (OSV)
red hat:compat-libpthread-nonshared0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-all-langpacks0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-benchtests0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-common0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-devel0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-doc0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-gconv-extra0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-langpack-aa0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-langpack-af0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-langpack-agr0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-langpack-ak0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:glibc-langpack-am0:2.42-11.1.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-366 · Race Condition within a Thread

CVSS vector

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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (4 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records