CVE-2026-123783 Details
Description
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.
A sandbox bypass vulnerability has been identified in Skyvern versions through 1.0.56. This vulnerability allows authenticated users to execute arbitrary code by reconstructing functions from raw bytecode using types.CodeType. The exploitation involves deploying scripts that bypass the is_safe_script_code AST denylist, enabling the import of restricted modules like subprocess or socket to execute code within the Skyvern server process.
Users can update to Skyvern version 1.0.57 or later, where this vulnerability has been addressed.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 6, 2026CISA-ADP
Assessed Nov 6, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/Skyvern-AI/skyvern | [email protected] | Vendor |
| https://github.com/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/code_block_safety.py#L106-L142 | [email protected] | Source CodeVendor |
| https://github.com/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/service.py#L1509-L1511 | [email protected] | Source CodeVendor |
| https://github.com/Skyvern-AI/skyvern/commit/31a64c1a4b5dfaf1e76a7164845e10f2d68248dc | [email protected] | Source CodeVendor |
| https://github.com/Skyvern-AI/skyvern/issues/8927 | [email protected] | ExploitIssue TrackingTechnical DescriptionVendor |
| https://github.com/Skyvern-AI/skyvern/pull/8937 | [email protected] | Issue TrackingVendor |
| https://www.vulncheck.com/advisories/skyvern-through-1.0.56-script-sandbox-bypass-via-types-codetype-bytecode | [email protected] | AdvisoryBundleRemedy |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-184 | Incomplete List of Disallowed Inputs | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Skyvern | <= 1.0.56 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 6, 2026 | CVE Modified | CISA-ADP |
| Nov 6, 2026 | New CVE Received | [email protected] |