CVE-2026-105274
CVE-2026-105274 — hex_core decompresses registry and Erlang term API responses without size limits
Improper Handling of Highly Compressed Data (Data Amplification) vulnerability in hexpm hex_core allows an untrusted repository mirror, or a server answering hex_core's API requests, to exhaust the memory of the Erlang VM running hex_core. The same code is vendored in Hex (mix_hex_repo, mix_hex_api) and rebar3 (r3_hex_repo, r3_hex_api). hex_repo:get_names/1, hex_repo:get_versions/1, hex_repo:get_package/2 and hex_repo:get_policy/2 decompress the registry response with zlib:gunzip/1 and decode the signed envelope before verifying its signature. A mirror doesn't have the repository's private key, but it chooses the compressed bytes, so a small response decompresses into an envelope of any size before the signature check rejects it. hex_api decodes responses with the application/vnd.hex+erlang content type through hex_safe_binary_to_term:safe_binary_to_term/1, which calls…
Published Updated Sources: cvelistV5, EEF
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
0%
chance of exploitation in 30 days
CVSS base
2.1
LOW
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 2.1 | CVSS 4.0 | LOW | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-409
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /1, /2, /vnd.hex+erlang.
References
9 on the record
- github.com/hexpm/hex_core/security/advisories/GHSA-7c4r-cgf9-9jmq
related, vendor-advisory
- cna.erlef.org/cves/CVE-2026-105274.html
related
- osv.dev/vulnerability/EEF-CVE-2026-105274
related
- github.com/erlang/rebar3/commit/209c02ec57c2cc3207ee0174c3af3675b8dc8f79
related
- github.com/erlang/rebar3/commit/360838a22f5b3a88c0358207f2923059bcbb3afb
patch
- github.com/hexpm/hex_core/commit/fbb6d9de472e5edb8d6fb6b32a91cb266137892e
related
- github.com/hexpm/hex_core/commit/ebe25d110717f6a3addba5232cd4a7dc1c76b628
patch
- github.com/hexpm/hex/commit/671f695ac548ed01f5828c2a739ecaa942b21007
related
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.