6.5

CVE-2026-6238: gnu glibc Buffer Over-read

CVSS: 6.5v3.1MediumModified
AliasesUBUNTU-CVE-2026-6238DEBIAN-CVE-2026-6238CGA-24h8-fpmm-6mmj
Published 28-04-2026Last modified 15-10-2026
Open JSON

Vulnerability summary

CVE-2026-6238 is a medium (CVSS 6.5) Buffer Over-read vulnerability in gnu glibc. EPSS estimates a 0.44% chance of exploitation in the next 30 days, higher than 37.2% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.44%
0%100%
Low · +0.09 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 14 · Related 10
MGASA-2026-0391OPENSUSE-SU-2026:11140-1OPENSUSE-SU-2026:21228-1RHSA-2026:12740RHSA-2026:42694RHSA-2026:42733

Timeline

  1. 28-04-2026
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.0.1 to version 2.43 fail to validate the RDATA content against the RDATA length in a DNS response when processing A6, CERT, LOC, TKEY or TSIG records, which may allow an attacker to craft a DNS response, causing a target application to crash or read uninitialized memory. These functions are for application debugging only and hence not in the path of code executed by the DNS resolver. Further, they have been deprecated since version 2.34 and should not be used by any new applications. Applications should consider porting away from these interfaces since they may be removed in future versions.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.44%

Chance of exploitation in the next 30 days

Percentile

37%

Versus all other CVEs

30-day change

+0.09 pp

From 0.36% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.44%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Chainguard53 products
  • glibcAll versions (No fix recorded)
  • glibc-2.43All versions (No fix recorded)
  • glibc-2.43-abi-reportAll versions (No fix recorded)
  • glibc-2.43-devAll versions (No fix recorded)
  • glibc-2.43-iconvAll versions (No fix recorded)
Wolfi53 products
  • glibcAll versions (No fix recorded)
  • glibc-2.43All versions (No fix recorded)
  • glibc-2.43-abi-reportAll versions (No fix recorded)
  • glibc-2.43-devAll versions (No fix recorded)
  • glibc-2.43-iconvAll versions (No fix recorded)
Ubuntu2 products
  • eglibcAll versions (No fix recorded)
  • glibcAll versions (No fix recorded) | < 2.35-0ubuntu3.14 | < 2.39-0ubuntu8.8 | < 2.43-2ubuntu2.3
Debian1 product
  • glibcAll versions (No fix recorded) | < 2.43-3
Gnu1 product
  • glibc≥ 2.2 (No fix recorded)
The gnu c library1 product

6 vendors · 111 products

References

9 links