CVE-2026-67409
A public proof of concept exists; no exploitation attested.
- Published2026-09-25
- Fixed in4.3.3 · 4.2.9 · 4.1.14 · 4.0.23 · 3.13.18
- WeaknessCWE-252
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
RabbitMQ is a messaging and streaming broker. From 3.13.0 until 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18, JWKS Fetch Ignores HTTP Response Status Code - Signing Key Destruction Causes Authentication DoS (CWE-252). the JWKS key fetching mechanism in uaajwt.erl does not validate the HTTP response status code when downloading signing keys from the OAuth2 provider's JWKS endpoint. Non-200 responses (including 4xx and 5xx errors) are processed identically to successful responses. When the JWKS endpoint returns an error response with a valid-JSON body that lacks a keys field, all previously cached signing keys are destroyed, causing a persistent authentication denial of Files: deps/rabbitmqauthbackendoauth2/src/uaajwt.erl, lines 50-63 deps/rabbitmqauthbackendoauth2/src/uaajwks.erl, lines 5-7 deps/rabbitmqauthbackendoauth2/src/rabbitoauth2provider.erl, lines 98-107 Bug 1: HTTP status code ignored (uaajwt.erl:50-63): The Erlang httpc module returns {ok, {{HttpVersion, StatusCode, ReasonPhrase}, Headers, Body}}. The pattern {ok, {, , JwksBody}} matches ANY successful HTTP transaction Persistent authentication DoS: Once keys are destroyed, ALL OAuth2/JWT authentication fails for all users until a new successful JWKS refresh occurs Amplification: A single attacker can deny access to all legitimate OAuth2 users across the entire RabbitMQ. This issue is fixed in versions 4.3.3, 4.2.9, 4.1.14, 4.0.23, and 3.13.18.
Timeline
dates in UTC- 2026-09-2517:17CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-67409?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-67409?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 4.3 | ≥ 4.3.0, < 4.3.3 | 4.3.3 | NVD |
| 4.2 | ≥ 4.2.0, < 4.2.9 | 4.2.9 | NVD |
| 4.1 | ≥ 4.1.0, < 4.1.14 | 4.1.14 | NVD |
| 4.0 | ≥ 4.0.0, < 4.0.23 | 4.0.23 | NVD |
| 3.13 | ≥ 3.13.0, < 3.13.18 | 3.13.18 | NVD · OSV |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
rabbitmq-server: rabbitmq-server: Authentication Denial of Service via unvalidated JWKS HTTP response status codes
rabbitmq-server4.2.src as a component of Red Hat Hardened Images
Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update
Fix
- Update Broadcom rabbitmq server to 4.3.3 · 4.2.9 · 4.1.14 · 4.0.23 · 3.13.18
- Vendor fix Red Hat Product Security CVE-2026-67409 · 3 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/
- Workaround from the vendor Red Hat Product Security CVE-2026-67409 · 4 productsDisable the rabbitmq_auth_backend_oauth2 plugin and transition to internal username/password or mutual TLS (mTLS) authentication. Alternatively, place a reverse proxy in front of the JWKS endpoint to drop or sanitize non-200 HTTP responses before they reach RabbitMQ.
- No fix planned, says the vendor Red Hat Product Security CVE-2026-67409 · 1 productWill not fix
Advisories and patches
- github.comRelease Notes
- github.comRelease Notes
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- CVSS 4.0 vector
- CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Published
- 2026-09-25
- Last Modified
- 2026-10-08
- NVD status
- Analyzed
Frequently asked questions
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