CVE-2026-15311

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

Assigner: VulDB
Reserved: 09.07.2026 Published: 09.07.2026 Updated: 10.07.2026

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.

Metrics

CVSS Vector: 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
CVSS Score: 5.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:X/RC:C
CVSS Score: 3.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.1

CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N/E:P/RL:X/RC:C
CVSS Score: 3.5

Attack Vector	Network	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	None
Privileges Required	Low	Integrity Impact	Low
User Interaction	Required	Availability Impact	None

CVSS 3.0

CVSS Vector: AV:N/AC:L/Au:S/C:N/I:P/A:N/E:POC/RL:ND/RC:C
CVSS Score: 4

Access Vector	Network	Confidentiality Impact	None
Access Complexity	Low	Integrity Impact	Partial
Authentication	Single	Availability Impact	None

CVSS 2.0

Product Status

Vendor	NousResearch
Product	hermes-agent
Versions	Version 2026.5.29.0 is affected Version 2026.5.29.1 is affected Version 2026.5.29.2 is affected

Vendor

NousResearch

Product

hermes-agent

Versions

Version 2026.5.29.0 is affected
Version 2026.5.29.1 is affected
Version 2026.5.29.2 is affected

Credits

Eric-d (VulDB User) reporter
VulDB CNA Team coordinator

References

Problem Types