CVE-2026-86471
CRITICAL 9.3An unvalidated runtime configuration value in Apache CouchDB 3.5.2 and below on all platforms allows a CouchDB server admin to run arbitrary shell commands as the CouchDB operating system user. Users are recommended to upgrade to version 3.5.3, which fixes this issue.
Severe if exploited (CVSS 9.3), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.6%chance of exploitation in 30 days · 49th percentile
Impact if exploited
9.3CVSS 4.0 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓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
No public PoC is currently catalogued.
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Data snapshot:
Weakness (CWE)
- CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:A/S:N/AU:Y/R:U/V:C/RE:M/U:Red
References and research data (JSON)
All CVSS metrics
- CRITICAL 9.3 v4.0 · CNA Primary
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:A/S:N/AU:Y/R:U/V:C/RE:M/U:Red - CRITICAL 9.3 v4.0 · NVD Secondary
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:L/SC:H/SI:H/SA:L/E:A/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:Red
References
Patches & mitigations
- https://lists.apache.org/thread.html/pj83174r8f8f64odf47fwhozbfjtot0f CVE record · apache · Updated 2026-10-20T15:38:09.681Z
NVD · CVE-2026-86471 · Updated 2026-10-21T04:18:11.080
Advisories
- https://lists.apache.org/thread/c8p73gswgogtnzvk7hpw8jb8d4mnosdp CVE record · apache · Updated 2026-10-20T15:38:09.681Z
NVD · CVE-2026-86471 · Updated 2026-10-21T04:18:11.080 - https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-105155 EUVD · EUVD-2026-105155
Technical & other
- http://www.openwall.com/lists/oss-security/2026/10/20/11CVE record · CVE · Updated 2026-10-20T18:10:04.288Z
NVD · CVE-2026-86471 · Updated 2026-10-21T04:18:11.080