CVE-2026-90797

Apache CouchDB: Pre-authentication gzip decompression bomb via POST /_session

7.7 HighFix available

An unlimited gzip decompression routine in chttpd in Apache CouchDB 3.5.2 and below on all platforms allows any remote client to cause a denial of service via memory exhaustion. 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: None
Integrity: None
Availability: High

Exploit likelihood

0.67%Unchanged since Oct 21, 2026

What each source reports

CVE List Score used 7.7

Apache CouchDB: Pre-authentication gzip decompression bomb via POST /_session

Record: CVE-2026-90797
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U/S:N/AU:Y/R:A/V:D/RE:M/U:Red
Weakness: CWE-409
Updated: 2026-11-02

EUVDEUVD-2026-105156 7.7

Record: EUVD-2026-105156
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U/S:N/AU:Y/R:A/V:D/RE:M/U:Red
Updated: 2026-11-02

GitHub AdvisoriesGHSA-r5m6-9384-3274 7.7

An unlimited gzip decompression routine in chttpd in Apache CouchDB 3.5.2 and below on all...

Record: GHSA-r5m6-9384-3274
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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:A/V:D/RE:M/U:Red
Weakness: CWE-409
Updated: 2026-11-02

NVD 7.7

Record: CVE-2026-90797
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/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:A/V:D/RE:M/U:Red
Weakness: CWE-409
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-90797 7.7

Record: UBUNTU-CVE-2026-90797
CVSS 4.0: 7.7 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:U/S:N/AU:Y/R:A/V:D/RE:M/U:Red
Updated: 2026-11-02

OSVBIT-couchdb-2026-90797 No score

Apache CouchDB: Pre-authentication gzip decompression bomb via POST /_session

Record: BIT-couchdb-2026-90797
Updated: 2026-11-02

Affected products

apache software foundation couchdb

Affected packages

Affected packages
Package	Affected	Fixed
`couchdb` Bitnami	before 3.5.3	3.5.3
`couchdb` Ubuntu:16.04:LTS	All versions, plus listed versions 1.6.0-0ubuntu7	None known

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-90797 is a high vulnerability (CVSS 7.7) 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 0.67%, the 52nd percentile. Fixed in couchdb 3.5.3.