CVE-2026-9354
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.
INFO
Published Date :
May 24, 2026, 4:15 a.m.
Last Modified :
May 24, 2026, 4:15 a.m.
Remotely Exploit :
No
Source :
VulDB
Affected Products
The following products are affected by CVE-2026-9354
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Validate and sanitize all external inputs.
- Update the agent software to the latest version.
- Apply vendor-provided security patches immediately.
- Review agent code for similar vulnerabilities.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-9354 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-9354 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by [email protected]
May. 24, 2026
Action Type Old Value New Value Added 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L Added CVSS V2 (AV:N/AC:L/Au:N/C:N/I:P/A:P) Added CWE CWE-74 Added CWE CWE-116 Added Reference https://gist.github.com/YLChen-007/e90fb38ac03284176bae49898a3a46a4 Added Reference https://vuldb.com/submit/812226 Added Reference https://vuldb.com/vuln/365317 Added Reference https://vuldb.com/vuln/365317/cti