CVE-2026-81856 Affecting erlang-hex package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published13 Oct 2026
- disclosed12 Oct 2026
Introduced: 12 Oct 2026
NewCVE-2026-81856 (opens in a new tab)How to fix?
There is no fixed version for Echo:latest erlang-hex.
NVD Description
Note: Versions mentioned in the description apply only to the upstream erlang-hex package and not the erlang-hex package as distributed by Echo.
See How to fix? for Echo:latest relevant fixed versions and status.
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.
Hex 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.
This issue affects hex: from 0.0.1 before 2.5.2.
References
- https://advisory.echohq.com/cve/CVE-2026-81856
- 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