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Fencer Intel
medium 5.7

CVE-2026-86692 json

apport: Arbitrary file creation or overwrite via path traversal in base64-encoded problem report keys

published 2d ago modified 2d ago also EUVD-2026-120401

cvss
5.7
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 5%
public exploits
0
none known

Summary

In apport before 2.37.0, a path traversal vulnerability allows an attacker who can supply a crafted crash report to cause unintended file creation or overwrite outside the intended extraction directory when the report is processed with apport-unpack.

The key-name validation added for CVE-2026-77113 does not cover base64-encoded keys skipped by ProblemReport.load(binary=False), and ProblemReport.extract_keys() writes them to a file path built from the key without validation. This allows an attacker to create or overwrite arbitrary files writable by the invoking user, such as .bashrc or .profile, gaining persistence or code execution in that user's context.

Patch / fix

  • Canonical apport 2.37.0

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Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 5% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 5.7 CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:P/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N

Affected products

  • Canonical apport

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.