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Fencer Vulns
high 7.5

CVE-2026-46385 json

iskorotkov/avro: CPU Exhaustion in Avro Decoder

published 2026-05-18 5 mo ago modified 2026-09-10 1 mo ago also GHSA-w8j3-pq8g-8m7w , GO-2026-5046 , EUVD-2026-33444

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

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.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.

Patch / fix

  • go github.com/iskorotkov/avro/v2 2.33.0
  • Red Hat Cryostat 4 on RHEL 9 4.2.0-19
  • Red Hat Multicluster Global Hub 1.4.5 1784060681
  • Red Hat Multicluster Global Hub 1.6.5 1784561376
  • Red Hat Multicluster Global Hub 1.7.0 1784906628, 1785442872
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.11 1783578847
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.13 1782383730
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16 1786908968
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17 1787316467
  • Red Hat Red Hat multicluster global hub 1.5.3 1784562060
  • govulncheck-vulndb SLES 16.0, SLES for SAP applications 16.0 0.0.20260727T201416-160000.1.1

suse advisories SUSE-SU-2026:23216-1SUSE-SU-2026:23227-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260727T201416-160000.1.1

opensuse advisories openSUSE-SU-2026:21551-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46385 updated cvss 7.5

github.com/hamba/avro/v2: github.com/linkedin/goavro/v2: CPU Exhaustion in Avro Decoder via Unbounded Block-Count Iteration

  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-storage-rhel9 4.2.0-19
    fixed: vendor fix RHSA-2026:48151
  • Red Hat Multicluster Global Hub 1.4.9 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1784060681
    fixed: vendor fix RHSA-2026:41030
  • Red Hat Multicluster Global Hub 1.5.8 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1784562060
    fixed: vendor fix RHSA-2026:42852
  • Red Hat Multicluster Global Hub 1.6.6 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1784561376
    fixed: vendor fix RHSA-2026:44622
  • Red Hat Multicluster Global Hub 1.7.4 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1784906628, multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1785442872
    fixed: vendor fix RHSA-2026:47149
  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/acm-grafana-rhel9 1783578847
    fixed: vendor fix RHSA-2026:41064
  • Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/acm-grafana-rhel9 1782383730
    fixed: vendor fix RHSA-2026:30651
  • Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/acm-grafana-rhel9 1786908968
    fixed: vendor fix RHSA-2026:57191
show 4 more
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/acm-grafana-rhel9 1787316467
    fixed: vendor fix RHSA-2026:60386
  • Red Hat Cryostat 4 on RHEL 9 cryostat/cryostat-rhel9 4.2.0-13, cryostat/cryostat-db-rhel9 4.2.0-19, cryostat/jfr-datasource-rhel9 4.2.0-13, cryostat/cryostat-reports-rhel9 4.2.0-13, cryostat/cryostat-rhel9-operator 4.2.0-18, cryostat/cryostat-operator-bundle 4.2.0-11, +3 more Red Hat Multicluster Global Hub 1.4.9 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1784061472, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1784061010, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1784060515, multicluster-globalhub/multicluster-globalhub-operator-bundle 1784064050, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1784061953 Red Hat Multicluster Global Hub 1.5.8 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1784127491, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1784128029, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1784127524, multicluster-globalhub/multicluster-globalhub-operator-bundle 1784565261, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1784127173 Red Hat Multicluster Global Hub 1.6.6 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1784152046, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1784151884, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1784151772, multicluster-globalhub/multicluster-globalhub-operator-bundle 1784728578, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1784152164 Red Hat Multicluster Global Hub 1.7.4 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1784768332, multicluster-globalhub/multicluster-globalhub-agent-rhel9 1785775948, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1784768150, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1785773056, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1784307548, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1785773214, +3 more Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/thanos-rhel9 1784105699, rhacm2/console-rhel9 1783350952, rhacm2/prometheus-rhel9 1784022042, rhacm2/acm-search-v2-rhel9 1783327407, rhacm2/node-exporter-rhel9 1784018382, rhacm2/observatorium-rhel9 1783640394, +34 more
    +3 more products
    Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/thanos-rhel9 1782465412, rhacm2/acm-cli-rhel9 1782157113, rhacm2/console-rhel9 1782157514, rhacm2/prometheus-rhel9 1782374537, rhacm2/acm-search-v2-rhel9 1782316482, rhacm2/node-exporter-rhel9 1782157546, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/thanos-rhel9 1786909435, rhacm2/acm-cli-rhel9 1786908319, rhacm2/console-rhel9 1786908361, rhacm2/prometheus-rhel9 1786909036, rhacm2/acm-search-v2-rhel9 1786909139, rhacm2/node-exporter-rhel9 1786908949, +40 more Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/thanos-rhel9 1787229716, rhacm2/acm-cli-rhel9 1787227626, rhacm2/console-rhel9 1787335105, rhacm2/prometheus-rhel9 1787230287, rhacm2/acm-search-v2-rhel9 1787681651, rhacm2/node-exporter-rhel9 1787230187, +39 more
    not affected: vulnerable code not present
  • Red Hat Enterprise Linux 8 grafana, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, grafana-graphite, +8 more Red Hat Enterprise Linux 9 grafana, grafana-selinux Red Hat Enterprise Linux 10 grafana
    not affected: component not present
  • Red Hat Hardened Images opentelemetry-collector-contrib
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/iskorotkov/avro/security/advisories/GHSA-w8j3-pq8g-8m7w referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 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
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/iskorotkov/avro/v2
<2.33.0
2.33.0
go github.com/hamba/avro/v2
all versions
 no fix listed

Affected products

  • iskorotkov avro
  • Red Hat Cryostat 4 on RHEL 9
  • Red Hat Multicluster Global Hub 1.4.5
  • Red Hat Multicluster Global Hub 1.6.5
  • Red Hat Multicluster Global Hub 1.7.0
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.11
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.13
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17
  • Red Hat Red Hat multicluster global hub 1.5.3
  • 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

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-835 Loop with Unreachable Exit Condition
  • CWE-1284 Improper Validation of Specified Quantity in Input

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.