Erlang hex: Improper Validation of Integrity Check Value vulnerability in hexpm hex allows a package mirror to
Affects erlang-hexSource GCVE Database
Not known to be exploited · CVSS 6.9 Medium.
Data as of 28 Oct 2026, 22:31 UTC
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:H/VA:N/SC:N/SI:H/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 12 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10erlang-hexpkg:deb/ubuntu/erlang-hex?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSerlang-hexpkg:deb/ubuntu/erlang-hex?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSerlang-hexpkg:deb/ubuntu/erlang-hex?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
Improper Validation of Integrity Check Value vulnerability in hexpm hex allows a package mirror to substitute the tarball that mix hex.package fetch PACKAGE VERSION --output - writes to standard output. Hex compares a fetched tarball's inner and outer checksums with the repository's signed registry before writing it to a file or unpacking it. The standard output branch of mix hex.package fetch writes the bytes returned by Hex.SCM.fetch/3 without that comparison, and Hex.SCM.fetch/3 doesn't verify freshly downloaded tarballs itself. When a mirror configured with HEX_MIRROR_URL or mirror_url serves altered bytes, the command prints them and exits successfully, while the same fetch with --output FILE fails with a checksum mismatch. Hex also prints diagnostics to standard output while the command runs: the body of a failed HTTP response from the update check or a registry fetch, and API warnings from the x-hex-message header. A mirror that answers one of those requests with an error whose body is a tar archive gets that archive written to standard output ahead of the verified tarball, so a pipeline that unpacks standard output extracts the mirror's files. This happens even when the checksum check then fails, because the archive is already on standard output. This issue affects hex: from 0.20.2 before 2.5.2.
References
- ubuntu.com/security/CVE-2026-105280 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-105280 (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-105280.html (opens in a new tab)
- github.com/hexpm/hex/commit/69489f8b74213f03db10169e6e5407e6d5fee512 (opens in a new tab)
- github.com/hexpm/hex/commit/8a14632ca6ba8a8afd2a3f2098bc267c13e13d93 (opens in a new tab)
- github.com/hexpm/hex/commit/d1f5a085d9d4748e1f7d195e4bc39ebd77c28d9c (opens in a new tab)
- github.com/hexpm/hex/security/advisories/GHSA-98jr-23pm-vj7c (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-105280 (opens in a new tab)