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TI-2026-12886 Aliases CVE-2026-15311GHSA-93m6-38r7-vqmh

NousResearch hermes-agent Matrix Adapter matrix.py MatrixAdapter._markdown_to_html cross site scripting

Priority MEDIUM 56CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting, Code execution
Confidentiality · integrity · availability
None · Low · None
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79 and CWE-94.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00356 29th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by the CNA
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
NousResearchhermes-agent2026.5.29.0; 2026.5.29.1; 2026.5.29.2—No fix listedCNA
  • hermes-agent VendorNousResearch Affected 2026.5.29.0; 2026.5.29.1; 2026.5.29.2 Fixed in — No fix listed CNA

CPE names CNA · 1

CPEVersionsRoleVendor
cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*——NousResearch
  • cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:* Versions — — ·NousResearch

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-15311
  2. 2026-10-03 Alias added: GHSA-93m6-38r7-vqmh

References

Exploit 1

Patch 1

Other 1

  • TI-2026-50258 Hermes Agent 0.18.2 - 0.21.0 RCE via git core.fsmonitor Config Injection CVSS 4.0HIGH 8.6
  • TI-2026-12325 NousResearch hermes-agent Live Webhook Endpoint base.py extract_media path traversal CVSS 4.0MEDIUM 6.9
  • TI-2026-08962 NousResearch hermes-agent Webhook Endpoint feishu.py _handle_webhook_request resource consumption CVSS 4.0MEDIUM 6.9
  • TI-2026-08959 NousResearch hermes-agent run_agent.py _compress_context injection CVSS 4.0MEDIUM 6.9
  • TI-2026-08958 NousResearch hermes-agent skills_tool.py skill_view injection CVSS 4.0MEDIUM 6.9
  • TI-2026-08218 NousResearch hermes-agent Environment Variable code_execution_tool.py execute_code sandbox CVSS 4.0MEDIUM 6.9
See all 44 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences