Vulnerability in Skyvern-Ai Skyvern
CVE-2026-123783
Skyvern through 1.0.56 contains a sandbox bypass vulnerability that allows authenticated users to execute code by reconstructing functions from raw bytecode with types.CodeType. Attackers can deploy scripts that evade the is_safe_script_code AST denylist and import blocked modules such as subprocess or socket to run code in the Skyvern server process.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/Skyvern-AI/skyvern (product)
- Script AST denylist (technical-description)
- Script module execution (technical-description)
- Fix commit 31a64c1 (patch)
- GitHub Issue #8927 (issue-tracking)
- Fix pull request #8937 (issue-tracking, patch)
- VulnCheck Advisory: Skyvern through 1.0.56 Script Sandbox Bypass via types.CodeType Bytecode (third-party-advisory)
Frequently asked questions
- What is CVE-2026-123783?
- CVE-2026-123783 is a high-severity vulnerability in Skyvern-Ai Skyvern, classified under Incomplete List of Disallowed Inputs. CVSS score: 8.8/10. Published 2026-11-06.
- How severe is CVE-2026-123783?
- High severity. CVSS v3 base score is 8.8 out of 10.