CVE-2026-18661
HIGH 8.8 PoC AVAILABLEIn Eclipse Jetty, across various versions of `jetty-annotations`, and `jetty-eeN-annotations`, the Jakarta Spec authoritative url-pattern rules for mixed `@ServletSecurity` annotation, and `web.xml` defined `security-constraint` on the same `url-pattern` were not being applied if the `web.xml` had more than 1 `url-pattern` for a servlet, and had a `security-constraint` applying to only some of those `url-pattern` definitions.
Public exploit or PoC code exists. Modeled probability is still low, but the barrier to attack is reduced — watch closely.
Exploitation likelihood
0.3%chance of exploitation in 30 days · 25th percentile
Impact if exploited
8.8CVSS 4.0 · HIGH
- ConfidentialityHigh
- IntegrityLow
- AvailabilityNone
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ✓Requirements: No special attack requirements
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- reference https://github.com/jetty/jetty.project/security/advisories/GHSA-v6xf-996f-c35f
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-18661/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-2026-18661/poc.json
Weakness (CWE)
- CWE-863: Incorrect authorization
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
All CVSS metrics
- HIGH 8.8 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N - HIGH 8.8 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:L/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