Bug 2463539 (CVE-2026-6238) - CVE-2026-6238 glibc: glibc: Application crash or uninitialized memory read via crafted DNS response
Summary: CVE-2026-6238 glibc: glibc: Application crash or uninitialized memory read vi...
Keywords:
Status: NEW
Alias: CVE-2026-6238
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-04-28 19:09 UTC by OSIDB Bzimport
Modified: 2026-07-31 08:01 UTC (History)
7 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2026:47045 0 None None None 2026-07-28 11:24:09 UTC
Red Hat Product Errata RHBA-2026:48661 0 None None None 2026-07-30 08:37:38 UTC
Red Hat Product Errata RHBA-2026:48662 0 None None None 2026-07-30 11:23:58 UTC
Red Hat Product Errata RHSA-2026:42694 0 None None None 2026-07-21 11:58:21 UTC
Red Hat Product Errata RHSA-2026:42733 0 None None None 2026-07-21 14:23:32 UTC
Red Hat Product Errata RHSA-2026:42952 0 None None None 2026-07-22 02:46:26 UTC

Description OSIDB Bzimport 2026-04-28 19:09:53 UTC 
The deprecated functions ns_printrrf, ns_printrr and fp_nquery in the GNU C Library version 2.2 and newer fail to validate the RDATA content against the RDATA length in a DNS response when processing LOC, CERT, 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.
Comment 3 errata-xmlrpc 2026-07-21 11:58:20 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 10

Via RHSA-2026:42694 https://access.redhat.com/errata/RHSA-2026:42694
Comment 4 errata-xmlrpc 2026-07-21 14:23:31 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2026:42733 https://access.redhat.com/errata/RHSA-2026:42733
Comment 5 errata-xmlrpc 2026-07-22 02:46:25 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 9

Via RHSA-2026:42952 https://access.redhat.com/errata/RHSA-2026:42952
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