Elixir protobuf: Unbounded recursion depth in embedded-message decoding
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- Present
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-674.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| elixir-protobuf | protobuf | 0.8.0 to before 0.16.1 | 0.16.1 | Patch available | CNA |
| — | protobuf (Hex) | 0.8.0 to before 0.16.1 | 0.16.1 | Patch available | GHSA-rv48-qqj5-crxg |
- protobuf Vendorelixir-protobuf Affected 0.8.0 to before 0.16.1 Fixed in 0.16.1 Patch available CNA
- protobuf (Hex) Vendor— Affected 0.8.0 to before 0.16.1 Fixed in 0.16.1 Patch available GHSA-rv48-qqj5-crxg
Remediation
- Fix · CNA protobuf (elixir-protobuf) Fixed in 0.16.1
- Fix · GHSA-rv48-qqj5-crxg protobuf (Hex) Fixed in 0.16.1 Advisory →
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
Not affected: 2 products
- Red Hat Hardened Images
- Red Hat OpenShift Container Platform 4
Timeline
- 2026-10-02 Threatist record created from CVE-2026-54451
- 2026-10-03 Alias added: GHSA-rv48-qqj5-crxg
- 2026-10-24 Affected versions changed · Red Hat
References
Other 6
- https://github.com/elixir-protobuf/protobuf/security/advisories/GHSA-rv48-qqj5-crxg
- https://github.com/elixir-protobuf/protobuf/commit/352d1769a0ef575a8d18c3f9620609efdb73e2bc
- https://github.com/elixir-protobuf/protobuf/commit/b8efa97790eece3d2d0e8e7c31a45ed409fe5338
- https://github.com/elixir-protobuf/protobuf/releases/tag/v0.16.1
- https://github.com/elixir-protobuf/protobuf/commit/21ec7c5bec4fec74e10c1de0d5d1a2d8152ac5d4
- https://github.com/elixir-protobuf/protobuf
More elixir-protobuf vulnerabilities
- TI-2026-69888 Uncontrolled recursion in elixir-protobuf JSON decoding CVSS 4.0HIGH 8.2
Sources
- CVE-2026-54451 · CVE Program
- CVE-2026-54451 · NVD
- FIRST EPSS
- GHSA-rv48-qqj5-crxg · GitHub Advisory Database · CC BY 4.0
- CVE-2026-54451 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences