CVSS 4.0
6.3 mediumCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:NCVE-2026-90771
Medium (6.3). EPSS 0.4% chance of exploitation in the next 30 days. Fixed in joi 17.13.8, 18.2.9.
joi before versions 17.13.8 and 18.2.9 contains a prototype pollution vulnerability in the messages compilation function that accepts __proto__ as an error code. Attackers can supply __proto__ keys in custom messages to replace the returned object's prototype, breaking downstream code relying on Object.prototype methods.
Severity
CVSS 3.1
3.7 lowCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-31)
- CWE
- CWE-1321
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-wr44-6hxh-3jwq | npm | joi | <17.13.8 | 17.13.8 |
| GHSA-wr44-6hxh-3jwq | npm | joi | >=18.0.0 <18.2.9 | 18.2.9 |
References
- https://github.com/hapijs/joi
- https://github.com/hapijs/joi/blob/v18.2.8/lib/messages.js
- https://github.com/hapijs/joi/commit/5b8333c9177e08b4ef4ed02903c2d657084e7afb
- https://github.com/hapijs/joi/issues/3150
- https://www.vulncheck.com/advisories/joi-before-17.13.8-and-18.2.9-prototype-pollution-via-messages