Quick answers
- Is CVE-2026-84425 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-84425 being exploited in the wild.
- How severe is CVE-2026-84425?
- Medium severity, with a CVSS score of 4.3, published 2 September 2026.
- Which products and versions are affected?
- Zhayujie CowAgent up to 2.1.3.
- Is there a fix for CVE-2026-84425?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-84425 attacked?
- It is attacked over the network.
- Am I affected by CVE-2026-84425?
- Check whether you run Zhayujie CowAgent at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
CowAgent maintains a process-wide shared BrowserService with a single worker thread that serializes all Playwright operations through a shared queue. The BrowserTool accepts user-controlled wait and evaluate arguments without enforcing reasonable time limits. An attacker can exploit this through prompt injection to cause the agent to call the browser tool with an extremely long wait timeout or long-running script evaluation. When the upstream client times out, the Playwright operation continues to occupy the shared browser thread, causing all subsequent browser operations to queue behind it and exceed their own client deadlines. The vulnerability occurs because caller timeouts do not propagate cancellation to the underlying browser task, and no per-operation time limits are enforced.
Affected products
- zhayujie CowAgent up to 2.1.3
Timeline
- 2026-09-02: disclosed: CVE-2026-84425 published
- 2026-09-02: other: Exploit code made public; vendor did not respond to early disclosure