CVSS 4.0
6.3 mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:NCVE-2026-16266
Medium (6.3). EPSS 0.4% chance of exploitation in the next 30 days.
Versions of the package mongo-object before 3.0.3 are vulnerable to Prototype Pollution via the expandKey() function in util.js. An attacker can modify the JavaScript prototype chain by supplying a crafted property path containing special keys such as __proto__.
Severity
CVSS 3.1
4.0 mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 36% of CVEs (scores of 2026-10-31)
- CWE
- CWE-1321
- Published
- Modified
- Record from
- the NVD, synced
References
- https://github.com/longshotlabs/mongo-object/blob/4f7a570f2a2fcfa9417b7870d5f859e9574ec73c/src/util.ts%23L251
- https://github.com/longshotlabs/mongo-object/commit/638314107d8b397e5453c28e41729522b3e8d67c
- https://github.com/longshotlabs/mongo-object/issues/27
- https://security.snyk.io/vuln/SNYK-JS-MONGOOBJECT-13816714
- https://github.com/longshotlabs/mongo-object/issues/27