iskorotkov/avro: CPU Exhaustion in Avro Decoder_CVE-2026-46385

8.7 / 10

HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Description

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.

Basic Information

ID CVE-2026-46385

Source GitHub_M

Published May 29, 2026 at 19:58

Affected Product

Vendor iskorotkov

Product avro

Version < 2.33.0

Affected Versions iskorotkov avro < 2.33.0

CWE Classification

CWE-400

References

github.com /iskorotkov/avro/security/advisories/GHSA-w8j3-pq8g-8m7w

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    "published": "2026-05-29T19:58:59.667Z",
    "modified": "2026-05-29T19:58:59.667Z",
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