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CVE-2026-124077 json

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

published 2d ago modified 2d ago also EUVD-2026-120399

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits
0
none known

Summary

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.

Patch / fix

  • Apache Software Foundation Apache Commons Codec 1.23.0

Is CVE-2026-124077 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Exploit prediction

0.25% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-11).

Affected products

  • Apache Software Foundation Apache Commons Codec

Classification

Weakness
  • CWE-158 Improper Neutralization of Null Byte or NUL Character

References

Sources

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