--- id: CVE-2026-46385 title: iskorotkov/avro is a fast Go Avro codec summary: >- 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.ReadBlockHea… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-400 - CWE-835 vendor: iskorotkov product: avro affected: - avro < 2.33.0 patched: - cryostat_4_on_rhel 9 - multicluster_global_hub 1.4.5 - multicluster_global_hub 1.6.5 - multicluster_global_hub 1.7.0 - advanced_cluster_management_for_kubernetes 2.11 - advanced_cluster_management_for_kubernetes 2.13 - advanced_cluster_management_for_kubernetes 2.16 - advanced_cluster_management_for_kubernetes 2.17 - multicluster_global_hub 1.5.3 published: '2026-05-29' updated: '2026-09-09' sourceUpdated: '2026-09-09T13:20:17.253' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46385' references: - url: 'https://github.com/iskorotkov/avro/security/advisories/GHSA-w8j3-pq8g-8m7w' label: security-advisories@github.com - url: 'https://access.redhat.com/errata/RHSA-2026:30651' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:41030' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:41064' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:42852' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:44622' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:47149' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:48151' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:53530' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:57191' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/errata/RHSA-2026:60386' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://access.redhat.com/security/cve/CVE-2026-46385' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2483475' label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://github.com/iskorotkov/avro/security/advisories/GHSA-w8j3-pq8g-8m7w' label: 134c704f-9b21-4f2e-91b3-4a467353bcc0 - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46385.json label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c - url: 'https://www.cve.org/CVERecord?id=CVE-2026-46385' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-46385' tags: - nvd - cve.org - exploit-available - csaf - vex - red-hat exploitAvailable: true ssvc: exploitation: poc automatable: 'yes' technicalImpact: partial timestamp: '2026-06-01T16:22:43.598595Z' scores: nvd: 7.5 cna: 8.7 vendor: 7.5 epss: 0.00882 epssPercentile: 0.57371 ingestedAt: '2026-07-14T12:36:48.249Z' --- ## Overview 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. ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **RHSA-2026:48151** · Red Hat · fixed in: Cryostat 4 on RHEL 9 · released 2026-07-29 · [advisory](https://access.redhat.com/errata/RHSA-2026:48151) - **RHSA-2026:41030** · Red Hat · fixed in: Multicluster Global Hub 1.4.5 · released 2026-07-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:41030) - **RHSA-2026:44622** · Red Hat · fixed in: Multicluster Global Hub 1.6.5 · released 2026-07-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:44622) - **RHSA-2026:47149** · Red Hat · fixed in: Multicluster Global Hub 1.7.0 · released 2026-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2026:47149) - **RHSA-2026:53530** · Red Hat · fixed in: Multicluster Global Hub 1.7.0 · released 2026-08-11 · [advisory](https://access.redhat.com/errata/RHSA-2026:53530) - **RHSA-2026:41064** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.11 · released 2026-07-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:41064) - **RHSA-2026:30651** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.13 · released 2026-06-28 · [advisory](https://access.redhat.com/errata/RHSA-2026:30651) - **RHSA-2026:57191** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.16 · released 2026-08-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:57191) - **RHSA-2026:60386** · Red Hat · fixed in: Red Hat Advanced Cluster Management for Kubernetes 2.17 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:60386) - **RHSA-2026:42852** · Red Hat · fixed in: Red Hat multicluster global hub 1.5.3 · released 2026-07-21 · [advisory](https://access.redhat.com/errata/RHSA-2026:42852) - **Red Hat VEX** · Important · affected: Red Hat Hardened Images · no fix planned: Red Hat Hardened Images · updated 2026-09-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-46385.json)