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Fencer Vulns
high 7.5

CVE-2026-55677 json

Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files

published 2026-06-26 4 mo ago modified 2026-10-25 14 d ago also GHSA-vfp3-v2gw-7wfq , GO-2026-6293 , EUVD-2026-39800

cvss
7.5
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 44%
public exploits
0
none known

Summary

Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to bypass route-level access controls and read static files without authorization. This vulnerability is fixed in 4.15.3 and 5.2.0.

Patch / fix

  • go github.com/labstack/echo/v5 5.2.0
  • go github.com/labstack/echo/v4 4.15.3
  • osbuild-composer RHEL 9 165.1-5.el9_8
  • osbuild-composer-core RHEL 9 165.1-5.el9_8
  • osbuild-composer-worker RHEL 9 165.1-5.el9_8
  • osbuild-composer RHEL 8 101.5-3.el8_10
  • osbuild-composer-core RHEL 8 101.5-3.el8_10
  • osbuild-composer-worker RHEL 8 101.5-3.el8_10
  • osbuild-composer RHEL 10.2 165.1-5.el10_2
  • osbuild-composer-core RHEL 10.2 165.1-5.el10_2

red hat advisories RHSA-2026:69293RHSA-2026:67148RHSA-2026:66432RHSA-2026:63134RHSA-2026:61585RHSA-2026:57541

  • govulncheck-vulndb SLES for SAP applications 16.0, SLES 16.0 0.0.20260827T195228-160000.1.1

suse advisories SUSE-SU-2026:23625-1

  • govulncheck-vulndb openSUSE Leap 16.0 0.0.20260827T195228-160000.1.1

opensuse advisories openSUSE-SU-2026:21761-1

  • osbuild-composer AlmaLinux 9 165.1-5.el9_8.alma.1
  • osbuild-composer-core AlmaLinux 9 165.1-5.el9_8.alma.1
  • osbuild-composer-worker AlmaLinux 9 165.1-5.el9_8.alma.1
  • osbuild-composer AlmaLinux 8 101.5-3.el8_10.alma.1
  • osbuild-composer-core AlmaLinux 8 101.5-3.el8_10.alma.1
  • osbuild-composer-worker AlmaLinux 8 101.5-3.el8_10.alma.1
  • osbuild-composer AlmaLinux 10 165.1-5.el10_2.alma.1
  • osbuild-composer-core AlmaLinux 10 165.1-5.el10_2.alma.1

almalinux advisories ALSA-2026:69293ALSA-2026:67148ALSA-2026:66432

  • osbuild-composer Rocky Linux 9 165.1-5.el9_8.rocky.0.1
  • osbuild-composer Rocky Linux 8 101.5-3.el8_10.rocky.0.6
  • osbuild-composer Rocky Linux 10 165.1-5.el10_2.rocky.0.1

rocky linux advisories RLSA-2026:69293RLSA-2026:67148RLSA-2026:66432

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-2026-55677 updated cvss 7.5

github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy

  • Red Hat Ceph Storage 5 rhceph/rhceph-5-dashboard-rhel8
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Cluster Observability Operator 1.5 cluster-observability-operator/perses-rhel9 1787593946, cluster-observability-operator/perses-rhel9-operator 1787593697
    fixed: vendor fix RHSA-2026:61314
  • 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 Multicluster Global Hub 1.8.2 multicluster-globalhub/multicluster-globalhub-grafana-rhel9 1785443657
    fixed: vendor fix RHSA-2026:52946
  • Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2/acm-multicluster-observability-addon-rhel9 1787314816
    fixed: vendor fix RHSA-2026:60389
  • Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/acm-multicluster-observability-addon-rhel9 1787314813
    fixed: vendor fix RHSA-2026:60391
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/acm-multicluster-observability-addon-rhel9 1787314818
    fixed: vendor fix RHSA-2026:60386
show 17 more
  • Red Hat Enterprise Linux AppStream (v. 8) osbuild-composer 101.5-3.el8_10, osbuild-composer-core 101.5-3.el8_10, osbuild-composer-worker 101.5-3.el8_10
    fixed: vendor fix RHSA-2026:67148
  • Red Hat Enterprise Linux AppStream (v. 9) osbuild-composer 165.1-5.el9_8, osbuild-composer-core 165.1-5.el9_8, osbuild-composer-worker 165.1-5.el9_8
    fixed: vendor fix RHSA-2026:69293
  • Red Hat Enterprise Linux AppStream (v. 10) osbuild-composer 165.1-5.el10_2, osbuild-composer-core 165.1-5.el10_2, osbuild-composer-worker 165.1-5.el10_2
    fixed: vendor fix RHSA-2026:66432
  • Red Hat Enterprise Linux AppStream AUS (v.8.4) osbuild-composer 28.7-7.el8_4, osbuild-composer-core 28.7-7.el8_4, osbuild-composer-worker 28.7-7.el8_4
    fixed: vendor fix RHSA-2026:96076
  • Red Hat Enterprise Linux AppStream AUS (v.8.6) osbuild-composer 46.3-11.el8_6, osbuild-composer-core 46.3-11.el8_6, osbuild-composer-worker 46.3-11.el8_6, osbuild-composer-dnf-json 46.3-11.el8_6
    fixed: vendor fix RHSA-2026:90493
  • Red Hat Enterprise Linux AppStream E4S (v.8.8) osbuild-composer 75-12.el8_8, osbuild-composer-core 75-12.el8_8, osbuild-composer-worker 75-12.el8_8, osbuild-composer-dnf-json 75-12.el8_8
    fixed: vendor fix RHSA-2026:90363
  • Red Hat Enterprise Linux AppStream E4S (v.9.2) osbuild-composer 76.1-8.el9_2, osbuild-composer-core 76.1-8.el9_2, osbuild-composer-worker 76.1-8.el9_2, osbuild-composer-dnf-json 76.1-8.el9_2
    fixed: vendor fix RHSA-2026:61585
  • Red Hat Enterprise Linux AppStream E4S (v.9.4) osbuild-composer 101.3-4.el9_4.7, osbuild-composer-core 101.3-4.el9_4.7, osbuild-composer-worker 101.3-4.el9_4.7
    fixed: vendor fix RHSA-2026:91958
  • Red Hat Enterprise Linux AppStream EUS (v. 10.0) osbuild-composer 134.1-10.el10_0, osbuild-composer-core 134.1-10.el10_0, osbuild-composer-worker 134.1-10.el10_0
    fixed: vendor fix RHSA-2026:63134
  • Red Hat Enterprise Linux AppStream EUS (v.9.6) osbuild-composer 132.2-10.el9_6, osbuild-composer-core 132.2-10.el9_6, osbuild-composer-worker 132.2-10.el9_6
    fixed: vendor fix RHSA-2026:57541
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4) osbuild-composer 28.7-7.el8_4, osbuild-composer-core 28.7-7.el8_4, osbuild-composer-worker 28.7-7.el8_4
    fixed: vendor fix RHSA-2026:96076
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.6) osbuild-composer 46.3-11.el8_6, osbuild-composer-core 46.3-11.el8_6, osbuild-composer-worker 46.3-11.el8_6, osbuild-composer-dnf-json 46.3-11.el8_6
    fixed: vendor fix RHSA-2026:90493
  • Red Hat Enterprise Linux AppStream TUS (v.8.8) osbuild-composer 75-12.el8_8, osbuild-composer-core 75-12.el8_8, osbuild-composer-worker 75-12.el8_8, osbuild-composer-dnf-json 75-12.el8_8
    fixed: vendor fix RHSA-2026:90363
  • Red Hat Cluster Observability Operator 1.5 cluster-observability-operator/thanos-rhel9 1787594087, cluster-observability-operator/korrel8r-rhel9 1787593952, cluster-observability-operator/prometheus-rhel9 1787593705, cluster-observability-operator/alertmanager-rhel9 1787593799, cluster-observability-operator/logging-console-plugin-rhel9 1787593634, cluster-observability-operator/cluster-health-analyzer-rhel9 1787594138, +17 more 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 Multicluster Global Hub 1.8.2 multicluster-globalhub/multicluster-globalhub-agent-rhel9 1785763319, multicluster-globalhub/multicluster-globalhub-manager-rhel9 1785547017, multicluster-globalhub/multicluster-globalhub-rhel9-operator 1786067967, multicluster-globalhub/multicluster-globalhub-operator-bundle 1786372816, multicluster-globalhub/multicluster-globalhub-postgres-exporter-rhel9 1785973181 Red Hat Advanced Cluster Management for Kubernetes 2 rhacm2/acm-grafana-rhel9 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
    +2 more products
    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 Enterprise Linux 8 grafana, grafana-loki, grafana-mssql, grafana-mysql, grafana-selinux, grafana-graphite, +8 more
    not affected: vulnerable code not in execute path
  • Red Hat Enterprise Linux 9 grafana, grafana-selinux Red Hat Enterprise Linux 10 grafana
    not affected: component not present
  • Red Hat OpenShift Virtualization 4 container-native-virtualization/hyperconverged-cluster-webhook-rhel9, container-native-virtualization/hyperconverged-cluster-operator-rhel9
    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
4 mo ago

Exploit prediction

0.52% chance of exploitation in the next 30 days, higher than 44% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq 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:H/I:N/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
go github.com/labstack/echo/v5
<5.2.0
5.2.0
go github.com/labstack/echo/v4
<4.15.3
4.15.3
go github.com/labstack/echo
<=3.3.10
 no fix listed

Affected products

  • labstack echo

Classification

Weakness
  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory

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.