# CVE-2026-26833: thumbler Command Injection (Critical 9.8) 📦 📦 npm Not in CISA KEV CRITICAL severity # CVE-2026-26833 — thumbler CRITICAL CVE-2026-26833 is a critical-severity (CVSS 9.8) OS Command Injection vulnerability in thumbler. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime. thumbler allows OS Command Injection Published Mar 25, 2026 Updated Mar 31, 2026 Affected 1 pkg Patched See advisory Exploits None indexed Exploitation data as of Oct 13, 2026 · OSV.dev, NVD, FIRST.org (EPSS) ## Exploitation Status ### Proof-of-concept exploit code exists - CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation. - CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks. - A successful exploit gives an attacker total control of the affected component, not partial access. Exploitation and automatability from CISA’s SSVC triage for CVE-2026-26833. ## EPSS Exploitation Probability [via FIRST.org ↗](https://www.first.org/epss/) 3.3%probability of exploitation in next 30 days Lower Risk0.00% Lower risk than most CVEs88th percentile — riskier than 88% of all scored CVEsHighest risk 0.00%1.39%2.78%4.17%0.4%3.3%Apr 26Aug 26Oct 26 Probability of exploitation in the next 30 days, from [FIRST.org EPSS](https://www.first.org/epss/). ## How urgent is this, really ## Where this sits among everything scored ## Real-World Exposure 1 pkg affected How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched. 1other npm packages depend on this — each one inherits the vulnerability until it's patched upstream `thumbler`npm 124downloads / week ## Description thumbler through 1.1.2 allows OS command injection via the input, output, time, or size parameter in the thumbnail() function because user input is concatenated into a shell command string passed to child\_process.exec() without proper sanitization or escaping. ## Affected Packages 1 total Ecosystem Package Vulnerable range Fix 📦npm `thumbler` all versions No fix ## Affected Products 1 product · 1 configurations Application `thumbler`mmahrous ≤ 1.1.2 range ## Detection & mitigation playbook Open-source dependency 1. ### Detect Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for thumbler, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version. 2. ### Remediation status The records we use list no patched version of thumbler for CVE-2026-26833. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range. 3. ### Mitigate without a patch Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does. ## Frequently Asked Questions thumbler through 1.1.2 allows OS command injection via the input, output, time, or size parameter in the thumbnail() function because user input is concatenated into a shell command string passed to child\_process.exec() without proper sanitization or escaping. O3 Security · Impact-Aware SCA ### Is CVE-2026-26833 in your dependencies? Find it across npm, including transitive dependencies. [Scan my dependencies](/book-demo) [How O3 SCA works](/impact-aware-sca)