CVE-2026-33938
Handlebars 4.0.0–4.7.8 allows server-side JS execution via mutated @partial-block.
Is CVE-2026-33938 being exploited?
Not confirmed. CVE-2026-33938 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.71% probability of exploitation in the next 30 days.
How severe is CVE-2026-33938?
CVE-2026-33938 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-33938?
Yes. A fix has been recorded for CVE-2026-33938. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-33938 affect?
CVE-2026-33938 affects Handlebars.js 4.0.0–4.7.8. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-33938?
Upgrade to 4.7.9+ or use runtime build; audit helpers; limit untrusted input.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Server-side arbitrary JavaScript execution via crafted template AST in @partial-block.
Patch when possible
- affected>= 4.0.0 and < 4.7.9
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.