Vulnerability · Published Oct 10, 2026 · Assigned by VulnCheck

CVE-2026-108600open-multi-agent 1.5.0 through 1.21.2 Sandbox Escape via file_write Dangling Symlink

Medium 4.7

In plain English

A medium-severity security flaw in open-multi-agent from open-multi-agent. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 3.1)4.7Medium

Exploit odds (30 days)0.2%top 88.7% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

open-multi-agent (@open-multi-agent/core) 1.5.0 through 1.21.2 contains a link following vulnerability in the file_write tool sandbox that allows attackers to create files outside the workspace root by using dangling symlinks. Attackers can plant a dangling symlink in the workspace and steer the agent via prompt injection to write attacker-influenced content anywhere the agent process can write.

Affected products (as reported)

Vendor	Product	Versions
open-multi-agent	open-multi-agent	1.5.0 – through 1.21.2

Weakness: CWE-59 · Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N

References

https://hackmd.io/@haind/open-multi-agent-file-write-dangling-symlink-escape third-party-advisory
https://github.com/open-multi-agent/open-multi-agent/blob/6ec5498643c7e431aa66751f17f47a529e7f927c/packages/core/src/tool/built-in/path-safety.ts#L104-L113 technical-description
https://github.com/open-multi-agent/open-multi-agent/blob/6ec5498643c7e431aa66751f17f47a529e7f927c/packages/core/src/tool/built-in/file-write.ts#L67 technical-description
https://github.com/open-multi-agent/open-multi-agent product
VulnCheck Advisory: open-multi-agent 1.5.0 through 1.21.2 Sandbox Escape via file_write Dangling Symlink third-party-advisory