Anthropic Claude Code & Agent SDK OS Command Injection via promptEditor.ts
Summary
| CVE | CVE-2026-35021 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-04-06 20:16:25 UTC |
| Updated | 2026-04-13 20:16:34 UTC |
| Description | Anthropic Claude Code CLI and Claude Agent SDK contain an OS command injection vulnerability in the prompt editor invocation utility that allows attackers to execute arbitrary commands by crafting malicious file paths. Attackers can inject shell metacharacters such as $() or backtick expressions into file paths that are interpolated into shell commands executed via execSync. Although the file path is wrapped in double quotes, POSIX shell semantics (POSIX §2.2.3) do not prevent command substitution within double quotes, allowing injected expressions to be evaluated and resulting in arbitrary command execution with the privileges of the user running the CLI. |
Risk And Classification
Primary CVSS: v4.0 8.4 HIGH from [email protected]
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/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
EPSS: 0.000330000 probability, percentile 0.096140000 (date 2026-04-15)
Problem Types: CWE-78 | CWE-78 CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 8.4 | HIGH | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 8.4 | HIGH | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | [email protected] | Secondary | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 7.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
LocalAttack Complexity
LowAttack Requirements
NonePrivileges Required
NoneUser Interaction
ActiveConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
NoneSub Integrity
NoneSub Availability
NoneCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/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
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Anthropic | Claude Code | affected 2.1.91 semver | Not specified |
| CNA | Anthropic | Claude Agent SDK For Python | affected 0.1.55 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| phoenix.security/critical-ci-cd-nightmare-3-command-injection-flaws-in-claude-... | [email protected] | phoenix.security | |
| www.vulncheck.com/advisories/anthropic-claude-code-agent-sdk-os-command-injecti... | [email protected] | www.vulncheck.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Francesco Cipollone (en)
There are currently no legacy QID mappings associated with this CVE.