# CVE-2026-86692: apport: Arbitrary file creation or overwrite via path traversal in base64-encoded problem report keys

Status: published. Published: 2026-11-09. Updated: 2026-11-09.

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.

## Remediation

- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: canonical) — https://github.com/canonical/apport/pull/650
- fix: The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches. (source: CNA: canonical) — https://github.com/canonical/apport/commit/ca041037929ea3ebd3e0997dcedcf908ca3599a6

## Affected products and versions

- Canonical / apport (apport): ≥ 2.16.0; < 2.37.0 (affected, semver). Source: CNA: canonical; platforms: Linux

## Severity and prioritization

- CVSS 4.0: 5.7 (medium); 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; source: CNA: canonical

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-22

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/canonical/apport/pull/650 (CNA: canonical; patch)

- https://github.com/canonical/apport/commit/ca041037929ea3ebd3e0997dcedcf908ca3599a6 (CNA: canonical; patch)

- https://bugs.launchpad.net/ubuntu/+source/apport/+bug/2167360 (CNA: canonical; issue-tracking)

## Provenance

- CNA: canonical: https://www.cve.org/CVERecord?id=CVE-2026-86692; retrieved 2026-11-09; source updated 2026-11-09

Revision: 85d03764cef07094b2c697fe1f51a677ee58027a6471b3fca2866c48751ed38f

Canonical: https://y2.dev/cve/CVE-2026-86692

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