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Fencer Vulns
high 7.5

CVE-2026-33487 json

goxmldsig has validateSignature Loop Variable Capture Signature Bypass

published 2026-03-18 7 mo ago modified 2026-09-10 1 mo ago also GHSA-479m-364c-43vc , GO-2026-4753 , EUVD-2026-16281

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

goxmlsig provides XML Digital Signatures implemented in Go. Prior to version 1.6.0, the `validateSignature` function in `validate.go` goes through the references in the `SignedInfo` block to find one that matches the signed element's ID. In Go versions before 1.22, or when `go.mod` uses an older version, there is a loop variable capture issue. The code takes the address of the loop variable `_ref` instead of its value. As a result, if more than one reference matches the ID or if the loop logic is incorrect, the `ref` pointer will always end up pointing to the last element in the `SignedInfo.References` slice after the loop. goxmlsig version 1.6.0 contains a patch.

Patch / fix

  • go github.com/russellhaering/goxmldsig 1.6.0
  • Red Hat Multicluster Global Hub 1.3.4 1779212259
  • Red Hat Multicluster Global Hub 1.4.5 1779579439
  • Red Hat Multicluster Global Hub 1.6.5 1780167118
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.14 1782693386
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15 1777142269
  • Red Hat Red Hat multicluster global hub 1.5.3 1778867753
  • Red Hat Red Hat OpenShift GitOps 1.18 1779116359
  • Red Hat Red Hat OpenShift GitOps 1.19 1779209965
  • govulncheck-vulndb openSUSE Leap 15.6 0.0.20260402T184258-150000.1.158.1

suse advisories SUSE-SU-2026:1205-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
  • velociraptor openSUSE Tumbleweed 0.7.0.4.git185.a5708584-2.1

opensuse advisories openSUSE-SU-2026:21483-1openSUSE-SU-2026:11126-1

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-2026-33487 updated cvss 7.5

github.com/russellhaering/goxmldsig: goxmlsig: Integrity bypass due to incorrect XML Digital Signature validation via loop variable capture issue

  • Red Hat Multicluster Global Hub 1.3.4 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1779212259
    fixed: vendor fix RHSA-2026:22423
  • Red Hat Multicluster Global Hub 1.4.9 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1779579439
    fixed: vendor fix RHSA-2026:22347
  • Red Hat Multicluster Global Hub 1.5.8 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1778867753
    fixed: vendor fix RHSA-2026:21769
  • Red Hat Multicluster Global Hub 1.6.6 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1780167118
    fixed: vendor fix RHSA-2026:23345
  • Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/acm-grafana-rhel9 1782693386
    fixed: vendor fix RHSA-2026:36882
  • Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2 1777142269
    fixed: vendor fix RHSA-2026:13548
  • Red Hat OpenShift GitOps 1.18 openshift-gitops-1/dex-rhel8 1779116359
    fixed: vendor fix RHSA-2026:20946
  • Red Hat OpenShift GitOps 1.19 openshift-gitops-1/dex-rhel8 1779209965
    fixed: vendor fix RHSA-2026:20943
show 3 more
  • Red Hat Multicluster Global Hub 1.3.4 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1779210675, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1779210608, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1779209992, multicluster-globalhub/multicluster-globalhub-operator-bundle 1779925031, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1779924243 Red Hat Multicluster Global Hub 1.4.9 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1779838819, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1779839447, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1779887217, multicluster-globalhub/multicluster-globalhub-operator-bundle 1779891163, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1779147132 Red Hat Multicluster Global Hub 1.5.8 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1779828691, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1779828813, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1779828536, multicluster-globalhub/multicluster-globalhub-operator-bundle 1779837290, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1779835152 Red Hat Multicluster Global Hub 1.6.6 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1780320809, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1780321673, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1779839087, multicluster-globalhub/multicluster-globalhub-operator-bundle 1780370487, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1779839762 Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/thanos-rhel9 1783122371, rhacm2/acm-cli-rhel9 1783350872, rhacm2/console-rhel9 1783451729, rhacm2/prometheus-rhel9 1783259161, rhacm2/acm-search-v2-rhel9 1783381100, rhacm2/node-exporter-rhel9 1783327463, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2 1776395605, rhacm2 1776437108, rhacm2 1776440706, rhacm2 1776440738, rhacm2 1776555620, rhacm2 1776641849, +38 more
    not affected: vulnerable code not present
  • Red Hat Advanced Cluster Security 4 advanced-cluster-security/rhacs-main-rhel8, advanced-cluster-security/rhacs-roxctl-rhel8, advanced-cluster-security/rhacs-rhel8-operator, advanced-cluster-security/rhacs-scanner-v4-rhel8
    not affected: vulnerable code not in execute path
  • 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 Red Hat OpenShift GitOps 1.18 openshift-gitops-1/argocd-rhel8 1779115298, openshift-gitops-1/argocd-rhel9 1779116502, openshift-gitops-1/gitops-rhel8 1779116228, openshift-gitops-1/must-gather-rhel8 1779114978, openshift-gitops-1/argocd-agent-rhel8 1779115163, openshift-gitops-1/argo-rollouts-rhel8 1779116461, +4 more Red Hat OpenShift GitOps 1.19 openshift-gitops-1/argocd-rhel8 1779211724, openshift-gitops-1/argocd-rhel9 1779211476, openshift-gitops-1/gitops-rhel8 1779210473, openshift-gitops-1/must-gather-rhel8 1779209869, openshift-gitops-1/argocd-agent-rhel8 1779210454, openshift-gitops-1/argo-rollouts-rhel8 1779210058, +5 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
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
7 mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/russellhaering/goxmldsig/security/advisories/GHSA-479m-364c-43vc referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/russellhaering/goxmldsig
<1.6.0
1.6.0

Affected products

  • russellhaering goxmldsig
  • Red Hat Multicluster Global Hub 1.3.4
  • Red Hat Multicluster Global Hub 1.4.5
  • Red Hat Multicluster Global Hub 1.6.5
  • 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 multicluster global hub 1.5.3
  • Red Hat Red Hat OpenShift GitOps 1.18
  • Red Hat Red Hat OpenShift GitOps 1.19
  • Red Hat Red Hat Advanced Cluster Security 4
  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9

Classification

Weakness
  • CWE-347 Improper Verification of Cryptographic Signature
  • CWE-682 Incorrect Calculation

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.