{"id":"CVE-2026-9354","state":"PUBLISHED","title":"NousResearch hermes-agent Slack Agent/Mattermost Agent escape output","description":"A vulnerability was detected in NousResearch hermes-agent up to 2026.4.16. The affected element is an unknown function of the component Slack Agent/Mattermost Agent. The manipulation of the argument format_message results in escaping of output. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.","publishedAt":"2026-05-24T04:15:07.598Z","updatedAt":"2026-05-27T17:28:00.312Z","severity":{"score":6.9,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P","source":"VulDB"},"assigner":"VulDB","products":["NousResearch hermes-agent"],"affected":[{"vendor":"NousResearch","product":"hermes-agent","versions":[{"version":"2026.4.0","status":"affected"},{"version":"2026.4.1","status":"affected"},{"version":"2026.4.2","status":"affected"},{"version":"2026.4.3","status":"affected"},{"version":"2026.4.4","status":"affected"},{"version":"2026.4.5","status":"affected"},{"version":"2026.4.6","status":"affected"},{"version":"2026.4.7","status":"affected"},{"version":"2026.4.8","status":"affected"},{"version":"2026.4.9","status":"affected"},{"version":"2026.4.10","status":"affected"},{"version":"2026.4.11","status":"affected"},{"version":"2026.4.12","status":"affected"},{"version":"2026.4.13","status":"affected"},{"version":"2026.4.14","status":"affected"},{"version":"2026.4.15","status":"affected"},{"version":"2026.4.16","status":"affected"}],"cpes":["cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"],"modules":["Slack Agent/Mattermost Agent"]}],"references":["https://vuldb.com/vuln/365317","https://vuldb.com/vuln/365317/cti","https://vuldb.com/submit/812226","https://gist.github.com/YLChen-007/e90fb38ac03284176bae49898a3a46a4"],"weaknesses":["CWE-116","CWE-74"],"ingestedAt":"2026-10-29T20:13:52.441Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/9xxx/CVE-2026-9354.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-9354","state":"PUBLISHED","datePublished":"2026-05-24T04:15:07.598Z","dateUpdated":"2026-05-27T17:28:00.312Z","assignerShortName":"VulDB","assignerOrgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateReserved":"2026-05-23T09:19:41.024Z"},"containers":{"cna":{"title":"NousResearch hermes-agent Slack Agent/Mattermost Agent escape output","descriptions":[{"lang":"en","value":"A vulnerability was detected in NousResearch hermes-agent up to 2026.4.16. The affected element is an unknown function of the component Slack Agent/Mattermost Agent. The manipulation of the argument format_message results in escaping of output. The attack can be executed remotely. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way."}],"affected":[{"vendor":"NousResearch","product":"hermes-agent","versions":[{"version":"2026.4.0","status":"affected"},{"version":"2026.4.1","status":"affected"},{"version":"2026.4.2","status":"affected"},{"version":"2026.4.3","status":"affected"},{"version":"2026.4.4","status":"affected"},{"version":"2026.4.5","status":"affected"},{"version":"2026.4.6","status":"affected"},{"version":"2026.4.7","status":"affected"},{"version":"2026.4.8","status":"affected"},{"version":"2026.4.9","status":"affected"},{"version":"2026.4.10","status":"affected"},{"version":"2026.4.11","status":"affected"},{"version":"2026.4.12","status":"affected"},{"version":"2026.4.13","status":"affected"},{"version":"2026.4.14","status":"affected"},{"version":"2026.4.15","status":"affected"},{"version":"2026.4.16","status":"affected"}],"cpes":["cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*"],"modules":["Slack Agent/Mattermost Agent"]}],"references":[{"url":"https://vuldb.com/vuln/365317","name":"VDB-365317 | NousResearch hermes-agent Slack Agent/Mattermost Agent escape output","tags":["vdb-entry","technical-description"]},{"url":"https://vuldb.com/vuln/365317/cti","name":"VDB-365317 | CTI Indicators (IOB, IOC, IOA)","tags":["signature","permissions-required"]},{"url":"https://vuldb.com/submit/812226","name":"Submit #812226 | NousResearch hermes-agent 2026.4.16 Improper Encoding or Escaping of Output (CWE-116)","tags":["third-party-advisory"]},{"url":"https://gist.github.com/YLChen-007/e90fb38ac03284176bae49898a3a46a4","tags":["exploit"]}],"metrics":[{"cvssV4_0":{"version":"4.0","baseScore":6.9,"vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P","baseSeverity":"MEDIUM"}},{"cvssV3_1":{"version":"3.1","baseScore":6.5,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R","baseSeverity":"MEDIUM"}},{"cvssV3_0":{"version":"3.0","baseScore":6.5,"vectorString":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:P/RL:X/RC:R","baseSeverity":"MEDIUM"}},{"cvssV2_0":{"version":"2.0","baseScore":6.4,"vectorString":"AV:N/AC:L/Au:N/C:N/I:P/A:P/E:POC/RL:ND/RC:UR"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-116","type":"CWE","lang":"en","description":"Escaping of Output"}]},{"descriptions":[{"cweId":"CWE-74","type":"CWE","lang":"en","description":"Injection"}]}],"providerMetadata":{"shortName":"VulDB","orgId":"1af790b2-7ee1-4545-860a-a788eba489b5","dateUpdated":"2026-05-24T04:15:07.598Z"},"timeline":[{"time":"2026-05-23T00:00:00.000Z","lang":"en","value":"Advisory disclosed"},{"time":"2026-05-23T02:00:00.000Z","lang":"en","value":"VulDB entry created"},{"time":"2026-05-23T11:24:56.000Z","lang":"en","value":"VulDB entry last update"}],"credits":[{"lang":"en","value":"Eric-i (VulDB User)","type":"reporter"},{"lang":"en","value":"VulDB CNA Team","type":"coordinator"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-27T16:25:19.177335Z","id":"CVE-2026-9354","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-27T17:28:00.312Z"}}]}}}