CVE-2026-6238Public exploitNetwork attack vectorHinoki check available

Application crash or uninitialized-memory read via RDATA over-read

Published Apr 28, 2026 · Updated Apr 28, 2026

Buffer over-read in glibc 2.0.1 through 2.43 allows remote attackers to cause crashes or uninitialized-memory reads via crafted DNS replies. The deprecated ns_printrrf, ns_printrr, and fp_nquery debugging functions parse A6, CERT, LOC, TKEY, and TSIG RDATA without checking each field against the record's declared length. Exposure requires an application to call these formatting interfaces; the normal DNS resolver path does not call them.

CVSS severity6.5
Medium
EPSS probability0.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Buffer over-read in glibc 2.0.1 through 2.43 allows remote attackers to cause crashes or uninitialized-memory reads via crafted DNS replies. The deprecated ns_printrrf, ns_printrr, and fp_nquery debugging functions parse A6, CERT, LOC, TKEY, and TSIG RDATA without checking each field against the record's declared length. Exposure requires an application to call these formatting interfaces; the normal DNS resolver path does not call them.

The record

CVE
CVE-2026-6238
Published
Apr 28, 2026
Updated
Apr 28, 2026
Vendor
The GnuPG Project
Product
glibc
Classifications
CWE-126, CAPEC-598, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.2 <=0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The GnuPG Project · glibcversion=2.2 <=0

Published CVSS scores

6.5CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-126Buffer Over-read
CAPEC-598DNS Spoofing
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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