Elixir protobuf is a pure Elixir implementation of Google Protobuf. From 0.8.0 until 0.16.1, services that decode attacker-controlled protobuf bytes with Protobuf.Decoder can be taken offline when the schema contains a self-referential or cyclic message type. In lib/protobuf/decoder.ex, Protobuf.Decoder.value_for_field/3 handles an embedded?: true field by recursively entering the decode / build_message / handle_value / value_for_field call chain without enforcing a nesting-depth limit. Deeply nested embedded fields retain non-tail recursive frames, allowing a comparatively small request to consume substantial CPU and memory, pin a BEAM scheduler, and exhaust the node. This issue is fixed in version 0.16.1.
https://github.com/elixir-protobuf/protobuf/security/advisories/GHSA-rv48-qqj5-crxg
https://github.com/elixir-protobuf/protobuf/releases/tag/v0.16.1
https://github.com/elixir-protobuf/protobuf/commit/b8efa97790eece3d2d0e8e7c31a45ed409fe5338
https://github.com/elixir-protobuf/protobuf/commit/352d1769a0ef575a8d18c3f9620609efdb73e2bc
Published: 2026-09-17
Updated: 2026-09-17
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
Severity: Medium
Base Score: 7.5
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: High
Base Score: 8.2
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High
EPSS: 0.00301