CVE-2026-15311: medium-severity vulnerability in NousResearch hermes-agent
NousResearch hermes-agent Matrix Adapter matrix.py MatrixAdapter._markdown_to_html cross site scripting
Published · Updated
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33Vexday Risk Score
No sign of exploitation. It has a public proof of concept.
ssvc Attendcvss 5.1epss 0.4%
A vulnerability was identified in NousResearch hermes-agent up to 2026.5.29.2. Affected by this issue is the function MatrixAdapter._markdown_to_html of the file gateway/platforms/matrix.py of the component Matrix Adapter. Such manipulation leads to cross site scripting. The attack can be executed remotely. The exploit is publicly available and might be used. The pull request to fix this issue awaits acceptance.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
Affected products
NousResearch · hermes-agentpublic PoCs found — 1
cve_referencegithub.com/NousResearch/hermes-agent/issues/42667unverified⚠ Public resources, to assess the exposure of systems you control or are authorized to test. Test only with authorization.
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