CVE-2026-123783

CVSS 8.8 (high) · published 2026-11-06

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.

Weakness: CWE-184

Source: NVD CVE-2026-123783

References

• https://github.com/Skyvern-AI/skyvern
• https://github.com/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/code_block_safety.py#L106-L142
• https://github.com/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/service.py#L1509-L1511
• https://github.com/Skyvern-AI/skyvern/commit/31a64c1a4b5dfaf1e76a7164845e10f2d68248dc
• https://github.com/Skyvern-AI/skyvern/issues/8927
• https://github.com/Skyvern-AI/skyvern/pull/8937
• https://www.vulncheck.com/advisories/skyvern-through-1.0.56-script-sandbox-bypass-via-types-codetype-bytecode

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