CVE-2026-46385: Iskorotkov Avro

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

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 products

• Iskorotkov Avro: before 2.33.0 (fixed in 2.33.0)
• Red Hat Cryostat 4 On Rhel 9: before 4.2.0-19 (fixed in 4.2.0-19)
• Red Hat Multicluster Global Hub 1.4.5: before 1784060681 (fixed in 1784060681)
• Red Hat Multicluster Global Hub 1.6.5: before 1784561376 (fixed in 1784561376)
• Red Hat Multicluster Global Hub 1.7.0: before 1784906628 (fixed in 1784906628)
• Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.11: before 1783578847 (fixed in 1783578847)
• Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.13: before 1782383730 (fixed in 1782383730)
• Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.16: before 1786908968 (fixed in 1786908968)
• Red Hat Red Hat Advanced Cluster Management For Kubernetes 2.17: before 1787316467 (fixed in 1787316467)
• Red Hat Red Hat Enterprise Linux 10
• Red Hat Red Hat Enterprise Linux 8
• Red Hat Red Hat Enterprise Linux 9
• Red Hat Red Hat Hardened Images
• Red Hat Red Hat Multicluster Global Hub 1.5.3: before 1784562060 (fixed in 1784562060)

Published 2026-05-29. Last modified 2026-09-09.