Bug 2536605 (CVE-2026-54451)

Summary: CVE-2026-54451 protobuf: Elixir protobuf: Denial of Service via unbounded recursion in message decoding
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, sghai, sidsharm, suppawar, vlaad
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Elixir protobuf, a pure Elixir implementation of Google Protobuf. An attacker can craft protobuf messages with a self-referential or cyclic message type. When these messages are decoded by the `Protobuf.Decoder` component, specifically the `value_for_field` function, an unbounded recursion occurs due to the lack of a nesting-depth limit. This excessive recursion consumes substantial CPU and memory resources, leading to a Denial of Service (DoS) by taking the affected service offline.
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Description OSIDB Bzimport 2026-09-17 18:46:36 UTC 
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.