{"cve":"CVE-2026-81856","nvd":{"published":"2026-10-12T16:17:05.827","modified":"2026-10-16T18:18:37.903","status":"Deferred","description":"Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in hexpm hex allows a malicious package publisher or a hostile repository server to inject terminal control sequences into the output of Mix tasks.\n\nHex prints strings supplied by the package repository and the documentation search service straight to the terminal through Hex.Shell.info/1 and Hex.Shell.error/1, neutralizing no control characters. Affected sinks span package metadata and configuration snippets in mix hex.info, search results in mix hex.package search and mix hex.search, owner and organization listings, publish and sponsor URLs, the authenticated username in mix hex.user, policy identities in mix hex.policy, and API error bodies rendered by Hex.Utils.print_error_result/1. A malicious package can embed ANSI escape sequences (cursor movement, line erase, carriage returns, OSC 52 clipboard writes) or Unicode bidirectional overrides in any of those fields, so the bytes reach the terminal unchanged, forging displayed URLs, package descriptions and suggested commands, concealing real output, or writing to the clipboard. No authentication or privileged position is required; only publishing a package.\n\nThis issue affects hex: from 0.0.1 before 2.5.2.","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","score":2.3},"cvss_v3":null,"cwes":["CWE-150"],"references":["https://cna.erlef.org/cves/CVE-2026-81856.html","https://github.com/hexpm/hex/commit/211303e3f68f5d3ce06450c1ff1a7a770a9ab236","https://github.com/hexpm/hex/commit/dd3305ddf0032f6d0b468fd40dbbc3072bfcb8b8","https://github.com/hexpm/hex/security/advisories/GHSA-fpmj-3cxg-p766","https://osv.dev/vulnerability/EEF-CVE-2026-81856"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:58:52.678897993+00:00"},"epss":{"cve":"CVE-2026-81856","score":0.004,"percentile":0.33972,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}