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Fencer Vulns
medium 6.2

CVE-2026-18874 json

Volsync-addon-controller: volsync-addon-controller: annotation values rendered into yaml via text/template without escaping allows yaml injection into subscription

published 2026-08-19 2 mo ago modified 2026-10-26 14 d ago also EUVD-2026-62669

cvss
6.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 45%
public exploits
0
none known

Summary

A flaw was found in volsync-addon-controller. This vulnerability allows an attacker to inject malicious YAML (Yet Another Markup Language) code into the OpenShift Lifecycle Manager (OLM) Subscription resource. This is due to improper escaping of annotation values when they are rendered into YAML. Successful exploitation could lead to unauthorized modification or control over OLM Subscription configurations, potentially impacting software management within the cluster. This issue primarily affects systems where the 'volsync-addon-deploy-type: olm' annotation is explicitly enabled.

Patch / fix

  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.11 1787683560
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.13 1787266564
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.14 1787266564
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15 1787266360
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16 1787266564
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17 1787266556

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-2026-18874 updated cvss 6.2

volsync-addon-controller: volsync-addon-controller: annotation values rendered into YAML via text/template without escaping allows YAML injection into Subscription

  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/acm-volsync-addon-controller-rhel9 1787683560
    fixed: vendor fix RHSA-2026:60387
  • Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/acm-volsync-addon-controller-rhel9 1787266564
    fixed: vendor fix RHSA-2026:60390
  • Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/acm-volsync-addon-controller-rhel9 1787266564
    fixed: vendor fix RHSA-2026:60388
  • Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2/acm-volsync-addon-controller-rhel9 1787266360
    fixed: vendor fix RHSA-2026:60389
  • Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/acm-volsync-addon-controller-rhel9 1787266564
    fixed: vendor fix RHSA-2026:60391
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/acm-volsync-addon-controller-rhel9 1787266556
    fixed: vendor fix RHSA-2026:60386
  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/thanos-rhel9 1787685239, rhacm2/console-rhel9 1787687062, rhacm2/prometheus-rhel9 1787261499, rhacm2/acm-grafana-rhel9 1787682482, rhacm2/acm-search-v2-rhel9 1787688827, rhacm2/node-exporter-rhel9 1787263326, +34 more Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/thanos-rhel9 1787263906, rhacm2/acm-cli-rhel9 1787259085, rhacm2/console-rhel9 1787339249, rhacm2/prometheus-rhel9 1787263757, rhacm2/acm-grafana-rhel9 1787644958, rhacm2/acm-search-v2-rhel9 1787682112, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/thanos-rhel9 1787614805, rhacm2/acm-cli-rhel9 1786923505, rhacm2/console-rhel9 1787339248, rhacm2/prometheus-rhel9 1786976997, rhacm2/acm-grafana-rhel9 1787645355, rhacm2/acm-search-v2-rhel9 1787682033, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2/thanos-rhel9 1787238739, rhacm2/acm-cli-rhel9 1787238522, rhacm2/console-rhel9 1787341780, rhacm2/prometheus-rhel9 1787238666, rhacm2/acm-grafana-rhel9 1787645007, rhacm2/acm-search-v2-rhel9 1787681674, +39 more Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/thanos-rhel9 1786909435, rhacm2/acm-cli-rhel9 1786908319, rhacm2/console-rhel9 1787339213, rhacm2/prometheus-rhel9 1786909036, rhacm2/acm-grafana-rhel9 1787645431, rhacm2/acm-search-v2-rhel9 1787681686, +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-grafana-rhel9 1787316467, rhacm2/acm-search-v2-rhel9 1787681651, +39 more
    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
none
Automatable
no
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.54% chance of exploitation in the next 30 days, higher than 45% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.2 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:H/A:H

Affected products

  • 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 2.14
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code

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.