Bug 2483475 (CVE-2026-46385)

Summary: CVE-2026-46385 github.com/hamba/avro/v2: github.com/linkedin/goavro/v2: CPU Exhaustion in Avro Decoder via Unbounded Block-Count Iteration
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: aazores, alcohan, amctagga, aoconnor, bniver, cmah, eaguilar, ebaron, flucifre, gmeno, gparvin, groman, jbalunas, jolong, lchilton, mbenjamin, mhackett, pahickey, pjindal, rhaigner, rhel-process-autobot, sfeifer, sostapov, vereddy, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Avro array and map decoding logic in Go Avro. The decoder failed to properly stop processing after encountering read errors while iterating over attacker-controlled block-count values, leading to excessive resource consumption. A remote unauthenticated attacker could exploit this issue using specially crafted Avro payloads causing denial of service, where the affected system's CPU is consumed indefinitely until the process is terminated.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On: 2488856, 2488857, 2488858, 2488859, 2488860, 2488861    
Bug Blocks:    

Description OSIDB Bzimport 2026-05-29 21:02:00 UTC 
iskorotkov/avro is a fast Go Avro codec. Prior to 2.33.0, the Avro array and map decoders looped over an attacker-controlled block-count value without checking the underlying reader's error state inside the loop body. Reader.ReadBlockHeader returns the count as a Go int, which is 64-bit on amd64 / arm64 targets — so a producer can declare a block of up to math.MaxInt64 (~9.2 × 10¹⁸) elements followed by EOF (or any truncated payload), and the decoder will attempt that many no-op iterations before propagating the error. The realistic ceiling is "indefinite until the worker is killed externally" — a single hostile payload pins a CPU core until the process is OOM-killed, deadline-cancelled, or terminated. Remote, unauthenticated denial-of-service. This vulnerability is fixed in 2.33.0.