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Fencer Intel
high 7.5

CVE-2026-55677 json

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

published 4mo ago modified 17d ago also EUVD-2026-39800 , GHSA-vfp3-v2gw-7wfq , GO-2026-6293

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
  • labstack echo 4.15.3, 5.2.0
  • 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

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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
4mo ago

Exploit prediction

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

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 Intel 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.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.