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Fencer Vulns
medium 4.3

CVE-2026-84425 json

zhayujie CowAgent Browser Tool browser_tool.py BrowserTool denial of service

published 2026-09-02 2 mo ago modified 2026-09-02 2 mo ago also EUVD-2026-69781

cvss
4.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 40%
public exploits
0
none known

Summary

A vulnerability was found in zhayujie CowAgent up to 2.1.3. This impacts the function BrowserTool of the file agent/tools/browser/browser_tool.py of the component Browser Tool. Performing a manipulation results in denial of service. The attack can be initiated remotely. The exploit has been made public and could be used. The vendor was contacted early about this disclosure but did not respond in any way.

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 40% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/hackerguopeng/cve/tree/main/CowAgent_Browser_Evaluate_Wait_DoS_Report referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA 3.0 4.3 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L/E:P/RL:X/RC:R
CNA 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P/E:POC/RL:ND/RC:UR
CNA 4.0 2.1 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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
CNA 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
CNA 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Affected products

  • zhayujie CowAgent

Classification

Weakness
  • CWE-404 Improper Resource Shutdown or Release

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.