CVE-2026-123783 json
Skyvern through 1.0.56 Script Sandbox Bypass via types.CodeType Bytecode
published 2026-11-06 3 d ago modified 2026-11-06 3 d ago also EUVD-2026-118301
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- github.com/Skyvern-AI/skyvern@31a64c1 commit
- github.com/Skyvern-AI/skyvern#8937 pull request
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 3 d ago
Exploit prediction
0.56% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- Skyvern-AI skyvern
Classification
- Weakness
-
- CWE-184 Incomplete List of Disallowed Inputs
References
-
github.com
/Skyvern-AI/skyvern/pull/8937
issue-tracking, patch
-
github.com
/Skyvern-AI/skyvern/commit/31a64c1a4b5dfaf1e76a7164845e10f2d68248dc
patch
-
github.com
/Skyvern-AI/skyvern/issues/8927
issue-tracking
-
github.com
/Skyvern-AI/skyvern
product
-
github.com
/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/code_block_safety.py#L106-L142
technical-description
-
github.com
/Skyvern-AI/skyvern/blob/v1.0.56/skyvern/forge/sdk/workflow/service.py#L1509-L1511
technical-description
-
vulncheck.com
/advisories/skyvern-through-1.0.56-script-sandbox-bypass-via-types-codetype-bytecode
third-party-advisory
Sources
- CVE List CVE-2026-123783
- NVD CVE-2026-123783
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.