CVE-2026-21618
XSS in hexpm web view allows script injection in users' browsers.
Is CVE-2026-21618 being exploited?
Not confirmed. CVE-2026-21618 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 0.25% probability of exploitation in the next 30 days.
How severe is CVE-2026-21618?
CVE-2026-21618 is rated High with a CVSS score of 8.5. 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-2026-21618?
Yes. A fix has been recorded for CVE-2026-21618. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-21618 affect?
CVE-2026-21618 affects hexpm, hex.pm. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-21618?
Upgrade to the patched hexpm release
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Attacker can inject scripts via hexpm inputs, stealing cookies/sessions or impersonating users.
Patch when possible
- affected>= 2025-10-01 and < 2026-01-19
- affected>= 617e44c71f1dd9043870205f371d375c5c4d886d and < c692438684ead90c3bcbfb9ccf4e63c768c668a8
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.