Vulnerability · Published Oct 12, 2026 · Assigned by VulnCheck

CVE-2026-109375Vercel deepsec before 1.1.17 Arbitrary File Write via Symlink in Sandbox Tarball Extraction

Medium 6.1

In plain English

A medium-severity security flaw in deepsec from Vercel. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 25% of all known vulnerabilities).

Severity (CVSS 3.1)6.1Medium

Exploit odds (30 days)0.3%top 74.6% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Vercel deepsec from 0.1.0 before 1.1.17 contains a link following vulnerability in extractTarballLocally that allows sandboxed code to write files outside the sandbox by planting links in result tarballs. Attackers controlling sandbox code, such as a prompt-injected coding agent, can plant symbolic or hard links in the host data directory to write arbitrary files on the orchestrator host.

Affected products (as reported)

Vendor	Product	Versions
Vercel	deepsec	0.1.0 – before 1.1.17

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

References

GitHub Pull Request #46 issue-tracking, patch
GitHub Pull Request #47 patch, issue-tracking
Patch Commit patch
https://github.com/vercel-labs/deepsec product
VulnCheck Advisory: Vercel deepsec before 1.1.17 Arbitrary File Write via Symlink in Sandbox Tarball Extraction third-party-advisory