CVE-2026-15311 (GCVE-0-2026-15311)

Vulnerability from cvelistv5 – Published: 2026-07-09 23:45 – Updated: 2026-07-09 23:45
VLAI
Title
NousResearch hermes-agent Matrix Adapter matrix.py MatrixAdapter._markdown_to_html cross site scripting
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.
Severity
5.1 (Medium)
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
3.5 (Low)
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
3.5 (Low)
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
CWE
Assigner
References
Impacted products
Vendor Product Version
NousResearch hermes-agent Affected: 2026.5.29.0
Affected: 2026.5.29.1
Affected: 2026.5.29.2
    cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*
 Create a notification for this product.
Credits
Eric-d (VulDB User) VulDB CNA Team
Show details on NVD website
To clipboard 

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          ],
          "modules": [
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          ],
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          "vendor": "NousResearch",
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              "version": "2026.5.29.0"
            },
            {
              "status": "affected",
              "version": "2026.5.29.1"
            },
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            }
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        }
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          "tags": [
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          "tags": [
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          "url": "https://vuldb.com/cve/CVE-2026-15311"
        },
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        },
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          ],
          "url": "https://github.com/NousResearch/hermes-agent/issues/42667"
        },
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            "patch"
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          "url": "https://github.com/NousResearch/hermes-agent/pull/42759"
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          "time": "2026-07-09T02:00:00.000Z",
          "value": "VulDB entry created"
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          "lang": "en",
          "time": "2026-07-09T19:54:35.000Z",
          "value": "VulDB entry last update"
        }
      ],
      "title": "NousResearch hermes-agent Matrix Adapter matrix.py MatrixAdapter._markdown_to_html cross site scripting"
    }
  },
  "cveMetadata": {
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    "dateReserved": "2026-07-09T17:49:30.256Z",
    "dateUpdated": "2026-07-09T23:45:10.318Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.