CVE-2026-21618 Hex CVE debrief

Who should care

Users of Hexpm, especially those using versions between 2025-10-01 and 2026-01-19, should be aware of this vulnerability and take necessary actions to protect their systems. This includes updating Hexpm to a version beyond 2026-01-19 and reviewing current configurations to ensure proper input validation and sanitization.

Technical summary

The vulnerability is located in the 'Elixir.HexpmWeb.SharedAuthorizationView' modules, specifically in the 'render_grouped_scopes/3' routine. The affected program files include 'lib/hexpm_web/views/shared_authorization_view.ex'. The CVSS vector for this vulnerability is CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/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. This information is based on the supplied source corpus and official CVE record.

Defensive priority

High priority should be given to updating Hexpm to a version beyond 2026-01-19. Users should also review their current configurations and ensure that proper input validation and sanitization are in place.

Recommended defensive actions

• Update Hexpm to a version beyond 2026-01-19
• Review and enhance input validation and sanitization for web page generation
• Monitor systems for suspicious activity related to this vulnerability
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-01-19T15:15:50.693Z and was last modified on 2026-07-24T15:17:13.543Z. The NVD entry is currently Modified. This information is based on the supplied source corpus. The vulnerability affects hexpm versions from 2025-10-01 before 2026-01-19. Users should verify their systems for potential exposure and take necessary actions.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.