CVE-2026-35374

Published Apr 22, 2026

Last updated 21 days ago

CVSS medium 6.3

Overview

Description
A Time-of-Check to Time-of-Use (TOCTOU) vulnerability exists in the split utility of uutils coreutils. The program attempts to prevent data loss by checking for identity between input and output files using their file paths before initiating the split operation. However, the utility subsequently opens the output file with truncation after this path-based validation is complete. A local attacker with write access to the directory can exploit this race window by manipulating mutable path components (e.g., swapping a path with a symbolic link). This can cause split to truncate and write to an unintended target file, potentially including the input file itself or other sensitive files accessible to the process, leading to permanent data loss.
Source
security@ubuntu.com
NVD status
Analyzed
Products
coreutils

Risk scores

CVSS 3.1

Type
Secondary
Base score
6.3
Impact score
5.2
Exploitability score
1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:H
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 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
  2. 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
  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 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
  5. A logic error in the split utility of uutils coreutils causes the corruption of output filenames when provided with non-UTF-8 prefix or suffix inputs. The implementation utilizes to_string_lossy() when constructing chunk filenames, which automatically rewrites invalid byte sequences into the UTF-8 replacement character (U+FFFD). This behavior diverges from GNU split, which preserves raw pathname bytes intact. In environments utilizing non-UTF-8 encodings, this vulnerability leads to the creation of files with incorrect names, potentially causing filename collisions, broken automation, or the misdirection of output data.•CVE-2026-35375

References

Sources include official advisories and independent security research.