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CVE-2026-46385

iskorotkov/avro: CPU Exhaustion in Avro Decoder PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
iskorotkov / avroaffected < 2.33.0

CWE

CWE-400

References

ADP enrichment

CISA-ADP

No English description supplied.

redhat-SADP

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.