CVE-2026-35376

Published Apr 22, 2026

Last updated 21 days ago

CVSS medium 4.5

Overview

Description
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the chcon utility of uutils coreutils during recursive operations. The implementation resolves recursive targets using a fresh path lookup (via fts_accpath) rather than binding the traversal and label application to the specific directory state encountered during traversal. Because these operations are not anchored to file descriptors, a local attacker with write access to a directory tree can exploit timing-sensitive rename or symbolic link races to redirect a privileged recursive relabeling operation to unintended files or directories. This vulnerability breaks the hardening expectations for SELinux administration workflows and can lead to the unauthorized modification of security labels on sensitive system objects.
Source
security@ubuntu.com
NVD status
Analyzed
Products
coreutils

Risk scores

CVSS 3.1

Type
Primary
Base score
5.8
Impact score
4.7
Exploitability score
1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L
Severity
MEDIUM

Weaknesses

security@ubuntu.com
CWE-367

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. A logic error in the cut utility of uutils coreutils causes the utility to ignore the -s (only-delimited) flag when using the -z (null-terminated) and -d '' (empty delimiter) options together. The implementation incorrectly routes this specific combination through a specialized newline-delimiter code path that fails to check the record suppression status. Consequently, uutils cut emits the entire record plus a NUL byte instead of suppressing it. This divergence from GNU coreutils behavior creates a data integrity risk for automated pipelines that rely on cut -s to filter out undelimited data.•CVE-2026-35381
  2. A logic error in the cut utility of uutils coreutils causes the program to incorrectly interpret the literal two-byte string '' (two single quotes) as an empty delimiter. The implementation mistakenly maps this string to the NUL character for both the -d (delimiter) and --output-delimiter options. This vulnerability can lead to silent data corruption or logic errors in automated scripts and data pipelines that process strings containing these characters, as the utility may unintentionally split or join data on NUL bytes rather than the intended literal characters.•CVE-2026-35380
  3. A logic error in the tr utility of uutils coreutils causes the program to incorrectly define the [:graph:] and [:print:] character classes. The implementation mistakenly includes the ASCII space character (0x20) in the [:graph:] class and excludes it from the [:print:] class, effectively reversing the standard behavior established by POSIX and GNU coreutils. This vulnerability leads to unintended data modification or loss when the utility is used in automated scripts or data-cleaning pipelines that rely on standard character class semantics. For example, a command executed to delete all graphical characters while intending to preserve whitespace will incorrectly delete all ASCII spaces, potentially resulting in data corruption or logic failures in downstream processing.•CVE-2026-35379
  4. A logic error in the expr utility of uutils coreutils causes the program to evaluate parenthesized subexpressions during the parsing phase rather than at the execution phase. This implementation flaw prevents the utility from performing proper short-circuiting for logical OR (|) and AND (&) operations. As a result, arithmetic errors (such as division by zero) occurring within "dead" branches, branches that should be ignored due to short-circuiting, are raised as fatal errors. This divergence from GNU expr behavior can cause guarded expressions within shell scripts to fail with hard errors instead of returning expected boolean results, leading to premature script termination and breaking GNU-compatible shell control flow.•CVE-2026-35378
  5. A logic error in the env utility of uutils coreutils causes a failure to correctly parse command-line arguments when utilizing the -S (split-string) option. In GNU env, backslashes within single quotes are treated literally (with the exceptions of \\ and \'). However, the uutils implementation incorrectly attempts to validate these sequences, resulting in an "invalid sequence" error and an immediate process termination with an exit status of 125 when encountering valid but unrecognized sequences like \a or \x. This divergence from GNU behavior breaks compatibility for automated scripts and administrative workflows that rely on standard split-string semantics, leading to a local denial of service for those operations.•CVE-2026-35377

References

Sources include official advisories and independent security research.