# CVE-2026-56391: coreutils: GNU coreutils uniq is vulnerable to an out‑of‑bounds read due to incorrect handling of multibyte input when the -w (-... CVE-2026-56391 is fixed in 9 products on 1 platform, first by gnu-coreutils 9.7-3ubuntu2.1, released July 24, 2026. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2026-56391 - Priority: Routine - CVSS: 6.1 (moderate) - EPSS: 0.0013 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 24, 2026 ## Description 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. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | coreutils Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils RHEL 10 | 9.5-8.el10_2.1 | [RHSA-2026:67886](https://patchblox.com/security/data/fix/linux/rhsa-2026-67886.md) | Jul 24, 2026 | | Linux | coreutils almalinux 10 | 9.5-8.el10_2.1 | [ALSA-2026:67886](https://patchblox.com/security/data/fix/linux/alsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils ol 10 | 0:9.5-8.0.1.el10_2.1 | [ELSA-2026-67886](https://patchblox.com/security/data/fix/linux/elsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils opensuse-leap 16.0 | 9.6-160000.3.1 | [OPENSUSE-SU-2026:22147-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22147-1.md) | Nov 7, 2026 | | Linux | coreutils rocky 10 | 0:9.5-8.el10_2.1 | [RLSA-2026:67886](https://patchblox.com/security/data/fix/linux/rlsa-2026-67886.md) | Sep 17, 2026 | | Linux | coreutils sles 16.0 | 9.6-160000.3.1 | [SUSE-SU-2026:24268-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24268-1.md) | Nov 7, 2026 | | Linux | coreutils-common Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils-common almalinux 10 | 9.5-8.el10_2.1 | [ALSA-2026:67886](https://patchblox.com/security/data/fix/linux/alsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils-common ol 10 | 0:9.5-8.0.1.el10_2.1 | [ELSA-2026-67886](https://patchblox.com/security/data/fix/linux/elsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils-debuginfo Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils-debugsource Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils-single Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils-single almalinux 10 | 9.5-8.el10_2.1 | [ALSA-2026:67886](https://patchblox.com/security/data/fix/linux/alsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils-single ol 10 | 0:9.5-8.0.1.el10_2.1 | [ELSA-2026-67886](https://patchblox.com/security/data/fix/linux/elsa-2026-67886.md) | Sep 16, 2026 | | Linux | coreutils-single opensuse-leap 16.0 | 9.6-160000.3.1 | [OPENSUSE-SU-2026:22147-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22147-1.md) | Nov 7, 2026 | | Linux | coreutils-single sles 16.0 | 9.6-160000.3.1 | [SUSE-SU-2026:24268-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24268-1.md) | Nov 7, 2026 | | Linux | coreutils-single-debuginfo Fedora 43 | 9.7-10.fc43 | [FEDORA-2026-25427610BB](https://patchblox.com/security/data/fix/linux/fedora-2026-25427610bb.md) | Aug 3, 2026 | | Linux | coreutils-systemd opensuse-leap 16.0 | 9.6-160000.3.1 | [OPENSUSE-SU-2026:22147-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22147-1.md) | Nov 7, 2026 | | Linux | coreutils-systemd sles 16.0 | 9.6-160000.3.1 | [SUSE-SU-2026:24268-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-24268-1.md) | Nov 7, 2026 | | Linux | coreutils-testsuite opensuse-leap 16.0 | 9.6-160000.3.1 | [OPENSUSE-SU-2026:22147-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-22147-1.md) | Nov 7, 2026 | | Linux | gnu-coreutils Ubuntu 26.04.1 LTS (resolute) | 9.7-3ubuntu2.1 | [gnu-coreutils 9.7-3ubuntu2.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-gnu-coreutils-9.7-3ubuntu2.1.md) | Jul 24, 2026 | --- Data as of 2026-11-09T01:18:40Z UTC. 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