CVE-2026-90800
Apache CouchDB: Auth bypass in prefixed _users and _replicator databases
Missing 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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Apache CouchDB: Auth bypass in prefixed _users and _replicator databases
Missing 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.
- Record
CVE-2026-90800- CVSS 4.0
- 8.1 High
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 - Weakness
- CWE-862
- Updated
- 2026-11-02
EUVDEUVD-2026-105100
Missing 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.
- Record
EUVD-2026-105100- CVSS 4.0
- 8.1 High
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-49pc-3x56-3wp6
Missing authorisation checks in chttpd in Apache CouchDB 3.5.2 and below on all platforms allows...
Missing 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.
- Record
GHSA-49pc-3x56-3wp6- CVSS 4.0
- 8.1 High
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 - Weakness
- CWE-862
- Updated
- 2026-11-02
NVD
Missing 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.
- Record
CVE-2026-90800- CVSS 4.0
- 8.1 High
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 - Weakness
- CWE-862
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-90800
Missing 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.
- Record
UBUNTU-CVE-2026-90800- CVSS 4.0
- 8.1 High
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 - Updated
- 2026-11-02
OSVBIT-couchdb-2026-90800 No score
Apache CouchDB: Auth bypass in prefixed _users and _replicator databases
Missing 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.
- Record
BIT-couchdb-2026-90800- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-90800 is a high vulnerability (CVSS 8.1) in Apache Software Foundation Couchdb, published October 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.63%, the 50th percentile. Fixed in couchdb 3.5.3.
References
lists.apache.org/thread.html/pj83174r8f8f64odf47fwhozbfjtot0f
openwall.com/lists/oss-security/2026/10/20/15
nvd.nist.gov/vuln/detail/CVE-2026-90800
github.com/advisories/GHSA-49pc-3x56-3wp6
ubuntu.com/security/CVE-2026-90800
cve.org/CVERecord?id=CVE-2026-90800