6.1

CVE-2026-56391: gnu coreutils Out-of-bounds Read

CVSS: 6.1v3.1MediumAnalyzed
AliasesMGASA-2026-0439RHSA-2026:46515UBUNTU-CVE-2026-56391
Published 24-07-2026Last modified 24-07-2026
Open JSON

Vulnerability summary

CVE-2026-56391 is a medium (CVSS 6.1) Out-of-bounds Read vulnerability in gnu coreutils. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6% of scored vulnerabilities.

Overall risk
24/100
0100
Low · default modelHow is this calculated?
CVSS score
6.1/10
010
Medium · v3.1 (NVD)
EPSS score
0.17%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 3 · Related 2
OPENSUSE-SU-2026:11764-1RHSA-2026:67886USN-8697-1

Timeline

  1. 24-07-2026
    PublishedVulnerability first disclosed.
  2. 24-07-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

7 scores · 5 sources · 2 versions

EPSS trend

Probability

0.17%

Chance of exploitation in the next 30 days

Percentile

6%

Versus all other CVEs

30-day change

+0.04 pp

From 0.13% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.17%

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

Redhat3 products
  • coreutils< 0:9.11-5.1.hum1
  • coreutils-common< 0:9.11-5.1.hum1
  • coreutils-single< 0:9.11-5.1.hum1
Debian1 product
  • coreutilsAll versions (No fix recorded)
Gnu1 product
Mageia1 product
  • coreutils< 9.8-3.mga10
Ubuntu1 product
  • coreutils< 9.7-3ubuntu2.1

5 vendors · 7 products

References

18 links
Show all 18 references