Vulnerability · Published Jun 23, 2026 · Assigned by VulnCheck

CVE-2026-56696OpenHarness - Prompt Injection via /issue and /pr_comments Slash Commands

Medium 5.4

In plain English

A medium-severity missing authorization in OpenHarness from HKUDS. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.4%top 68.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

OpenHarness /issue and /pr_comments slash commands lack remote_invocable=False protection, allowing remote channel senders to write attacker-controlled Markdown into project context files. Admitted remote attackers can inject malicious content into .openharness/issue.md and .openharness/pr_comments.md files, which are subsequently injected into runtime system prompts, persistently influencing local agent behavior.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	openharness-ai	no fix listed	GHSA-24cw-228q-3rx9
PyPI	openharness-ai	no fix listed	PYSEC-2026-3880

Affected products (as reported)

Vendor	Product	Versions
HKUDS	OpenHarness	0 – through 0.1.9

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N

References

Pull Request issue-tracking
Patch Commit patch
https://www.vulncheck.com/advisories/openharness-prompt-injection-via-issue-and-pr-comments-slash-commands third-party-advisory