Skip to content
Fencer Vulns
high 7.4

CVE-2026-100351 json

kin-openapi: ValidationHandler security-requirement bypass via encoded-path operation confusion

published 2026-10-15 24 d ago modified 2026-11-05 3 d ago also GHSA-23vg-4cjm-66q5 , GO-2026-6769 , EUVD-2026-102160

cvss
7.4
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 42%
public exploits
0
none known

Summary

kin-openapi is a Go project for handling OpenAPI files. From 0.144.0 until 0.147.0, openapi3filter.ValidationHandler validates an operation selected from decoded URL.Path while a downstream gorilla/mux router configured with UseEncodedPath can dispatch a different operation selected from URL.RawPath. When a public exact route and a protected parameterized route use the same method and overlap after decoding, an unauthenticated remote request containing an encoded path separator can be validated as public and then dispatched to the protected handler without invoking the configured AuthenticationFunc. The reachable path parameter is constrained to an encoded representation that decodes to the public literal route, and proxies that canonicalize the URI before forwarding prevent this specific mismatch. This issue is fixed in version 0.147.0.

Patch / fix

  • go github.com/getkin/kin-openapi 0.147.0
  • grafana13.2 hummingbird 1 13.2.3-0.3.hum1
  • hugo hummingbird 1 0.168.0-0.1.hum1
  • grafana12.4 hummingbird 1 12.4.12-0.4.hum1

red hat advisories RHSA-2026:85266RHSA-2026:82637RHSA-2026:76677

  • timoni openSUSE Tumbleweed 0.36.0-1.1
  • hugo openSUSE Tumbleweed 0.168.0-2.1

opensuse advisories openSUSE-SU-2026:12309-1openSUSE-SU-2026:12164-1

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-2026-100351 updated cvss 7.4

github.com/getkin/kin-openapi: kin-openapi: Authentication bypass via URL path decoding discrepancy

  • Red Hat Hardened Images hugo 0.168.0-0.1.hum1, grafana13.1 13.1.8-0.3.hum1, grafana13.2 13.2.3-0.3.hum1, grafana12.4 12.4.12-0.4.hum1
    fixed: vendor fix RHSA-2026:76677
  • Red Hat Hardened Images go-fdo-server 1.0.2-1.1.hum1
    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
no
Technical impact
total
Assessed
24 d ago

Exploit prediction

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/getkin/kin-openapi/security/advisories/GHSA-23vg-4cjm-66q5 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem package affected fixed in
go github.com/getkin/kin-openapi
>=0.144.0, <0.147.0
0.147.0

Affected products

  • getkin kin-openapi

Classification

Weakness
  • CWE-289 Authentication Bypass by Alternate Name
  • CWE-436 Interpretation Conflict

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.