Secuno
ENNL
Book demo

CVE-2026-4437

Gnu Glibc out-of-bounds read

7.5 HIGHPublic exploitEPSS 0.33%
  1. Published20 Mar 2026

Description

Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C Library version 2.34 to version 2.43 could, with a crafted response from the configured DNS server, result in a violation of the DNS specification that causes the application to treat a non-answer section of the DNS response as a valid answer.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityNone
IntegrityNone
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Gnu Glibc≥ 2.34 ≤ 2.43

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1078378.2
RIOT is an open-source microcontroller operating system designed for Internet of Things…
CVE-2026-78269.1
A heap-based out-of-bounds read in the BufferSerializerIOv2_ReadBuffer function…
CVE-2026-823348.1
IBM Guardium Data Protection 12.0, 12.1, 12.2 is vulnerable to a heap-based…
CVE-2026-144968.2
IBM DataPower Gateway 10.5.0.0 through 10.5.0.22, 10.6.1 through 10.6.6, 10.6.0.0…
CVE-2026-764578.6
As part of Cisco's ongoing commitment to proactive security and product quality, the…
CVE-2026-772148.2
libexpat before commit 13c5f63 contains a heap buffer over-read vulnerability in…

Frequently asked

Is CVE-2026-4437 being actively exploited?

CVE-2026-4437 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.33%.

How severe is CVE-2026-4437?

CVE-2026-4437 has a CVSS 3.1 base score of 7.5, rated high. EPSS estimates a 0.33% probability of exploitation.

Which products are affected by CVE-2026-4437?

Affected products include Gnu Glibc.

How do I fix CVE-2026-4437?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-4437 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.