CVE-2026-4437

⚠️ high

Summary

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 Score

7.5

High

EPSS Score

0.1

Exploit Probability

Published Date

2026-03-20

First Seen: 2026-03-21

📊 Relative Risk Intelligence

This CVE is Moderate Risk - more severe than 68.9% of all 329,456 vulnerabilities in our database.

#102,448

Above average severity

Severity Percentile

🎯 CISA SSVC Assessment Updated: Mar 23, 2026

🔍 Exploitation Status

None

No known exploits

⚙️ Automatable

YES

Can be exploited automatically

💥 Technical Impact

Partial

Limited system impact

🏆 Discovered By

Antonio Maini (0rbitingZer0) - 0rbitingZer0@proton.me Kevin Farrell (reporter)

SSVC data provided by CISA

Last Modified 2026-04-07

Source NVD 🔗

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

CWE IDs (Weakness Types)

CWE-125

📦 Affected Products 1

Vendor	Product	Status	Affected Versions
gnu	glibc	Affected	> 2.34 < 2.43

🔗 References 1

https://sourceware.org/bugzilla/show_bug.cgi?id=34014

Exploit Issue Tracking Patch

🔗 Related CVEs 6

CVE ID	Severity	CVSS	EPSS	Summary	Published
CVE-2026-6238	🔶 medium	6.5	0.3	The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.0.1 to version 2.43 fail t...	2026-04-28
CVE-2026-5435	⚠️ high	7.3	0.1	The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.2 and newer fail to enforc...	2026-04-28
CVE-2026-4046	⚠️ high	7.5	0.0	The iconv() function in the GNU C Library versions 2.43 and earlier may crash due to an assertion failure when convertin...	2026-03-30
CVE-2026-4438	🔶 medium	5.4	0.1	Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the...	2026-03-20
CVE-2026-3904	🔶 medium	6.2	0.0	Calling NSS-backed functions that support caching via nscd may call the nscd client side code and in the GNU C Library ...	2026-03-11
CVE-2025-15281	⚠️ high	7.5	0.1	Calling wordexp with WRDE_REUSE in conjunction with WRDE_APPEND in the GNU C Library version 2.0 to version 2.42 may cau...	2026-01-20

These CVEs affect the same products