Bug 2507449

Summary:	CVE-2026-56391 coreutils: GNU coreutils uniq: Denial of Service and information disclosure via out-of-bounds read with multibyte input [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Ganesh <gnaik>
Component:	coreutils	Assignee:	Lukáš Zaoral <lzaoral>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	admiller, jamartis, kdudka, kzak, lzaoral, nixuser, ovasik, p, vmihalko
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["54809671-c38a-4098-9d24-669a2783072b"]}
Fixed In Version:	coreutils-9.11-6.fc45 coreutils-9.10-5.fc44 coreutils-9.7-10.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-08-03 09:23:24 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2506691

Description Ganesh 2026-07-27 12:05:08 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (--check-chars) option is used. The find_field() function miscalculates the byte length of characters by repeatedly processing a fixed pointer instead of advancing through the input, resulting in an inflated length value. 
This incorrect length is later used in a memcmp operation, causing reads beyond the allocated buffer when processing crafted multibyte input.

When running GNU coreutils uniq with attacker-provided arguments, this behavior leads to a crash and potential adjacent heap memory exposure.


This issue has been fixed in the commit d64e35a8a4c0e4608321433e0d84d917e4e36371.

Comment 1 Fedora Update System 2026-08-03 07:56:05 UTC

FEDORA-2026-217bb52eb2 (coreutils-9.11-6.fc45) has been submitted as an update to Fedora 45.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-217bb52eb2

Comment 2 Fedora Update System 2026-08-03 08:34:17 UTC

FEDORA-2026-36041358b1 (coreutils-9.10-5.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-36041358b1

Comment 3 Fedora Update System 2026-08-03 08:34:22 UTC

FEDORA-2026-25427610bb (coreutils-9.7-10.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-25427610bb

Comment 4 Fedora Update System 2026-08-03 09:23:24 UTC

FEDORA-2026-217bb52eb2 (coreutils-9.11-6.fc45) has been pushed to the Fedora 45 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 5 Fedora Update System 2026-08-04 01:40:56 UTC

FEDORA-2026-36041358b1 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-36041358b1`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-36041358b1

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 6 Fedora Update System 2026-08-04 02:00:03 UTC

FEDORA-2026-25427610bb has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-25427610bb`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-25427610bb

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2026-08-05 00:57:23 UTC

FEDORA-2026-36041358b1 (coreutils-9.10-5.fc44) has been pushed to the Fedora 44 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 8 Fedora Update System 2026-08-07 01:36:53 UTC

FEDORA-2026-25427610bb (coreutils-9.7-10.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.