Medium severity · published Jun 23, 2026
CVE-2026-56696
OpenHarness - Prompt Injection via /issue and /pr_comments Slash Commands
5.4
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 31% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenHarness · HKUDS
through 0.1.9 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-56696
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-56696
github.com
https://github.com/HKUDS/OpenHarness/commit/27bb93b810e9ea8fa4832eab7152eeb3b4a6bffb
github.com
https://github.com/HKUDS/OpenHarness/pull/272
www.vulncheck.com
https://www.vulncheck.com/advisories/openharness-prompt-injection-via-issue-and-pr-comments-slash-commands
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