Path Traversal in Halloy

CVE-2026-32733

Halloy is an IRC application written in Rust. Prior to commit 0f77b2cfc5f822517a256ea5a4b94bad8bfe38b6, the DCC receive flow did not sanitize filenames from incoming `DCC SEND` requests. A remote IRC user could send a filename with path traversal sequences like `../../.ssh/authorized_keys` and the file would be written outside the user's configured `save_directory`. With auto-accept enabled this required zero interaction from the victim. Starting with commit 0f77b2cfc5f822517a256ea5a4b94bad8bfe38b6, all identified code paths sanitize filenames through a shared `sanitize_filename` function.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.004 (32.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-32733?
CVE-2026-32733 is a medium-severity vulnerability in Halloy, classified under Path Traversal. CVSS score: 6.5/10. Published 2026-03-20.
How severe is CVE-2026-32733?
Medium severity. CVSS v3 base score is 6.5 out of 10.