CVE-2026-90800
HIGH 8.1Missing authorisation checks in chttpd in Apache CouchDB 3.5.2 and below on all platforms allows any request to read the full contents of a prefixed _user or _replicator database via an unauthorised API endpoint. The use of prefixed system databases is very rare. Users are recommended to upgrade to version 3.5.3, which fixes this issue.
Severe if exploited (CVSS 8.1), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.6%chance of exploitation in 30 days · 50th percentile
Impact if exploited
8.1CVSS 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: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
- ⚠Requirements: Specific conditions must be present
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-862: Missing Authorization
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:N/AU:Y/R:U/V:C/RE:M/U:Amber
References and research data (JSON)
All CVSS metrics
- HIGH 8.1 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/S:N/AU:Y/R:U/V:C/RE:M/U:Amber - HIGH 8.1 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N/E:U/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:N/AU:Y/R:U/V:C/RE:M/U:Amber
References
Patches & mitigations
- https://lists.apache.org/thread.html/pj83174r8f8f64odf47fwhozbfjtot0f CVE record · apache · Updated 2026-10-20T15:40:47.497Z
NVD · CVE-2026-90800 · Updated 2026-10-20T19:34:00.700
Advisories
- https://lists.apache.org/thread/vng8vqjwgy1qlrv14wzrgs7pv4gj7gwr CVE record · apache · Updated 2026-10-20T15:40:47.497Z
NVD · CVE-2026-90800 · Updated 2026-10-20T19:34:00.700 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-105100 EUVD · EUVD-2026-105100
Technical & other
- http://www.openwall.com/lists/oss-security/2026/10/20/15CVE record · CVE · Updated 2026-10-20T18:10:09.013Z
NVD · CVE-2026-90800 · Updated 2026-10-20T19:34:00.700