CVE-2026-0933: cloudflare wrangler Improper Input Validation

Vulnerability summary

CVE-2026-0933 is a critical (CVSS 9.9) Improper Input Validation vulnerability in cloudflare wrangler. EPSS estimates a 1.51% chance of exploitation in the next 30 days, higher than 74.1% of scored vulnerabilities.

Timeline

1. 20-01-2026
   PublishedVulnerability first disclosed.
2. 23-01-2026
   Last modifiedVulnerability information updated.

Description

SummaryA command injection vulnerability (CWE-78) has been found to exist in the `wrangler pages deploy` command. The issue occurs because the `--commit-hash` parameter is passed directly to a shell command without proper validation or sanitization, allowing an attacker with control of `--commit-hash` to execute arbitrary commands on the system running Wrangler. Root causeThe commitHash variable, derived from user input via the --commit-hash CLI argument, is interpolated directly into a shell command using template literals (e.g.,  execSync(`git show -s --format=%B ${commitHash}`)). Shell metacharacters are interpreted by the shell, enabling command execution. ImpactThis vulnerability is generally hard to exploit, as it requires --commit-hash to be attacker controlled. The vulnerability primarily affects CI/CD environments where `wrangler pages deploy` is used in automated pipelines and the --commit-hash parameter is populated from external, potentially untrusted sources. An attacker could exploit this to: * Run any shell command. * Exfiltrate environment variables. * Compromise the CI runner to install backdoors or modify build artifacts. Credits Disclosed responsibly by kny4hacker. Mitigation * Wrangler v4 users are requested to upgrade to Wrangler v4.59.1 or higher. * Wrangler v3 users are requested to upgrade to Wrangler v3.114.17 or higher. * Users on Wrangler v2 (EOL) should upgrade to a supported major version.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.