CVE-2026-9354 (GCVE-0-2026-9354)

Vulnerability from cvelistv5 – Published: 2026-05-24 04:15 – Updated: 2026-05-27 17:28
VLAI
Title
NousResearch hermes-agent Slack Agent/Mattermost Agent escape output
Summary
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.
Severity
6.9 (Medium)
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
6.5 (Medium)
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
6.5 (Medium)
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
CWE
Assigner
References
URL Tags
https://vuldb.com/vuln/365317 vdb-entrytechnical-description
https://vuldb.com/vuln/365317/cti signaturepermissions-required
https://vuldb.com/submit/812226 third-party-advisory
https://gist.github.com/YLChen-007/e90fb38ac03284… exploit
Impacted products
Vendor Product Version
NousResearch hermes-agent Affected: 2026.4.0
Affected: 2026.4.1
Affected: 2026.4.2
Affected: 2026.4.3
Affected: 2026.4.4
Affected: 2026.4.5
Affected: 2026.4.6
Affected: 2026.4.7
Affected: 2026.4.8
Affected: 2026.4.9
Affected: 2026.4.10
Affected: 2026.4.11
Affected: 2026.4.12
Affected: 2026.4.13
Affected: 2026.4.14
Affected: 2026.4.15
Affected: 2026.4.16
    cpe:2.3:a:nousresearch:hermes-agent:*:*:*:*:*:*:*:*
 Create a notification for this product.
Credits
Eric-i (VulDB User) VulDB CNA Team
Show details on NVD website
To clipboard 

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Taxonomy of the tags.




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.