Read the docs
TI-2026-74649 Aliases CVE-2026-100351GHSA-23vg-4cjm-66q5

Authentication bypass in kin-openapi via encoded URL paths

Priority HIGH 68CWE-289Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat.

Summary

kin-openapi from 0.144.0 before 0.147.0 is a Go module for handling OpenAPI files. The ValidationHandler in openapi3filter validates an operation chosen from the decoded URL path, while the gorilla/mux router with UseEncodedPath dispatches a different operation chosen from the encoded path, an interpretation conflict (CWE-436). An unauthenticated remote attacker can send a request with an encoded path separator to reach a protected handler without the configured AuthenticationFunc running.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00488 42nd percentileScored 2026-11-07
Fix Fixed kin-openapi (getkin): 0.147.0github.com/getkin/kin-openapi (Go): 0.147.0Red Hat: 4 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
getkinkin-openapi0.144.0 to before 0.147.00.147.0Patch availableCNA
—github.com/getkin/kin-openapi (Go)0.144.0 to before 0.147.00.147.0Patch availableGHSA-23vg-4cjm-66q5
  • kin-openapi Vendorgetkin Affected 0.144.0 to before 0.147.0 Fixed in 0.147.0 Patch available CNA
  • github.com/getkin/kin-openapi (Go) Vendor— Affected 0.144.0 to before 0.147.0 Fixed in 0.147.0 Patch available GHSA-23vg-4cjm-66q5

Remediation

Upgrade github.com/getkin/kin-openapi to version 0.147.0. The sources list no fixed version for kin-openapi. Red Hat Hardened Images RPMs fixes are listed in RHSA-2026:87077, RHSA-2026:85266, RHSA-2026:82637 and RHSA-2026:76677.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

  • Fix · CNA kin-openapi (getkin) Fixed in 0.147.0
  • Fix · GHSA-23vg-4cjm-66q5 github.com/getkin/kin-openapi (Go) Fixed in 0.147.0 Advisory →

Red Hat 4 advisories

  • RHSA-2026:87077 Released 2026-10-21 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images grafana13.1-13.1.8-0.3.hum1@aarch64, grafana13.1-13.1.8-0.3.hum1@s390x, grafana13.1-13.1.8-0.3.hum1@src +1
  • RHSA-2026:85266 Released 2026-10-19 · Red Hat rating Important
    Red Hat Hardened Images RPMs Security Update
    • Red Hat Hardened Images grafana13.2-13.2.3-0.3.hum1@aarch64, grafana13.2-13.2.3-0.3.hum1@s390x, grafana13.2-13.2.3-0.3.hum1@src +1
  • RHSA-2026:82637 Released 2026-10-14 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images hugo-0.168.0-0.1.hum1@aarch64, hugo-0.168.0-0.1.hum1@s390x, hugo-0.168.0-0.1.hum1@src +1
Show 1 more Red Hat advisories
  • RHSA-2026:76677 Released 2026-10-06 · Red Hat rating Important
    Red Hat Hardened Images RPMs bug fix and enhancement update
    • Red Hat Hardened Images grafana12.4-12.4.12-0.4.hum1@aarch64, grafana12.4-12.4.12-0.4.hum1@src, grafana12.4-12.4.12-0.4.hum1@x86_64

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Hardened ImagesFixed RHSA-2026:76677, RHSA-2026:82637, RHSA-2026:85266, RHSA-2026:87077
Not affected: 1 product
  • Red Hat Hardened Images

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-100351
  2. 2026-10-16 Alias added: GHSA-23vg-4cjm-66q5
  3. 2026-10-16 Fix available: RHSA-2026:82637 · Red Hat
  4. 2026-10-16 Fix available: RHSA-2026:76677 · Red Hat
  5. 2026-10-16 Fix available: Red Hat Hardened Images · Red Hat
  6. 2026-10-16 CVSS score added · Red Hat
  7. 2026-10-20 Fix available: RHSA-2026:85266 · Red Hat
  8. 2026-10-20 Affected versions changed · Red Hat
  9. 2026-10-22 Fix available: RHSA-2026:87077 · Red Hat
  10. 2026-10-22 Affected versions changed · Red Hat

References

Advisory 1

Other 4

  • TI-2026-51613 kin-openapi: ValidationHandler.Load() Fail-Open Authentication Bypass via NoopAuthenticationFunc Default CVSS 3.1CRITICAL 9.1
  • TI-2026-53976 kin-openapi: Uncontrolled resource consumption in openapi3filter deepObject query parameter decoding CVSS 4.0HIGH 8.7
  • TI-2026-74664 Nil pointer panic in kin-openapi openapi3filter decoding CVSS 3.1HIGH 7.5
  • TI-2026-74663 YAML NaN and Inf values cause panic in kin-openapi validation CVSS 3.1HIGH 7.5
  • TI-2026-74661 kin-openapi nil pointer panic in openapi3filter on array schemas without items CVSS 3.1HIGH 7.5
  • TI-2026-74657 Uncontrolled recursion in kin-openapi crashes the process CVSS 3.1HIGH 7.5
See all 13 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences