CVE-2026-124077

Apache Commons Codec: NUL bytes in tree entry names cause Git/SWHID identifier collisions (GitIdentifiers class)

Published Nov 9, 2026 CVSS 3.1 · 4.3 Medium EPSS < 1% KEV · Not listed
Description
The GitIdentifiers class in Apache Commons Codec did not reject NUL bytes in tree entry names. Because Git uses a NUL byte to mark the end of each entry name in a tree object, a crafted name could make one tree serialize to the same bytes as a different tree. Two different directory trees could then receive the same Git tree identifier or SWHID.



The impact is limited: common file systems do not allow NUL bytes in file names, so trees built by walking a file system are not affected. Only applications that build trees from names supplied by other sources, such as entries of archive formats that permit NUL bytes in names (e.g. ZIP) or names passed directly to the API, are exposed.



This issue affects Apache Commons Codec: from 1.22.0 before 1.23.0.



Users are recommended to upgrade to version 1.23.0, which fixes the issue.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N'}

Type Values Removed Values Added
First Time appeared Apache
Apache commons Codec
Vendors & Products Apache
Apache commons Codec
Type Values Removed Values Added
Description The GitIdentifiers class in Apache Commons Codec did not reject NUL bytes in tree entry names. Because Git uses a NUL byte to mark the end of each entry name in a tree object, a crafted name could make one tree serialize to the same bytes as a different tree. Two different directory trees could then receive the same Git tree identifier or SWHID. The impact is limited: common file systems do not allow NUL bytes in file names, so trees built by walking a file system are not affected. Only applications that build trees from names supplied by other sources, such as entries of archive formats that permit NUL bytes in names (e.g. ZIP) or names passed directly to the API, are exposed. This issue affects Apache Commons Codec: from 1.22.0 before 1.23.0. Users are recommended to upgrade to version 1.23.0, which fixes the issue.
Title Apache Commons Codec: NUL bytes in tree entry names cause Git/SWHID identifier collisions (GitIdentifiers class)
Weaknesses CWE-158
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
apache
Published
Updated
Nov 12, 2026, 5:33 PM
Reserved
Nov 6, 2026, 8:45 PM
Status
Awaiting Analysis
Published
Nov 9, 2026, 8:18 PM
Modified
Nov 12, 2026, 6:17 PM