CVE-2026-66070
HIGH 7.6RabbitMQ is a messaging and streaming broker. Prior to versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6, match_origin/1 returned the bare reflected Origin and allowed credentials even when the wildcard "" was configured, so the response echoed the attacker's origin together with Access-Control-Allow-Credentials. The affected code is rabbit_mgmt_cors.erl. When the management plugin is configured with a wildcard CORS origin (cors_allow_origins = ""), the handler reflects the request Origin back in Access-Control-Allow-Origin and also sends Access-Control-Allow-Credentials: true. A malicious web page that a signed-in administrator visits can then use that administrator's cached HTTP Basic credentials to issue authenticated, state-changing requests to the management API. Preconditions include The management plugin is configured with the wildcard cors_allow_origins = "*", which is an explicit operator misconfiguration A target administrator has a cached HTTP Basic-auth session in the browser. This issue is fixed in versions 3.13.17, 4.0.22, 4.1.13, and 4.2.6.
Severe if exploited (CVSS 7.6), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 34th percentile
Impact if exploited
7.6CVSS 4.0 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ⚠User interaction: Succeeds with passive user activity
- ✓Complexity: No special conditions — reliably repeatable
- ⚠Requirements: Specific conditions must be present
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-66070/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-66070/poc.json
Weakness (CWE)
- CWE-942: : Permissive Cross-domain Policy with Untrusted Domains
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Broadcom | Rabbitmq Server | ≥ 3.13.0 and < 3.13.17 |
| Broadcom | Rabbitmq Server | ≥ 4.0.0 and < 4.0.22 |
| Broadcom | Rabbitmq Server | ≥ 4.1.0 and < 4.1.13 |
| Broadcom | Rabbitmq Server | ≥ 4.2.0 and < 4.2.6 |
All CVSS metrics
- HIGH 7.6 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - HIGH 7.6 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:N/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 - HIGH 8.8 v3.1 · NVD Primary
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H