[Pkg-erlang-devel] Bug#1150901: rebar3: CVE-2026-105274

[Moritz Mühlenhoff]

Source: rebar3
X-Debbugs-CC: team at security.debian.org
Severity: important
Tags: security

Hi,

The following vulnerability was published for rebar3.

CVE-2026-105274[0]:
| 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
| binary_to_term(Binary, [safe]). The safe option prevents atom
| creation, but it accepts compressed terms and doesn't limit the size
| of the decoded term, and the check that rejects functions and ports
| runs after the term has been built. The fix for CVE-2026-21619 added
| the safe option and that check without bounding the decoded size.
| This issue affects rebar3: from 3.9.1 before 3.27.3; hex: from 2.1.0
| before 2.5.2; hex_core: from 0.1.0 before 0.20.0.

https://github.com/hexpm/hex_core/security/advisories/GHSA-7c4r-cgf9-9jmq
https://cna.erlef.org/cves/CVE-2026-105274.html
https://osv.dev/vulnerability/EEF-CVE-2026-105274

Fixed by: https://github.com/erlang/rebar3/commit/360838a22f5b3a88c0358207f2923059bcbb3afb (3.27.3)

If you fix the vulnerability please also make sure to include the
CVE (Common Vulnerabilities & Exposures) id in your changelog entry.

For further information see:

[0] https://security-tracker.debian.org/tracker/CVE-2026-105274
    https://www.cve.org/CVERecord?id=CVE-2026-105274

Please adjust the affected versions in the BTS as needed.