CVE-2026-39321
This timing difference allows an unauthenticated attacker to enumerate valid usernames.
Does this matter?
Lower severity and a low EPSS score (0.23%). Track it; it rarely justifies an emergency change on its own.
Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 9.8.0-alpha.6 and 8.6.74, he login endpoint response time differs measurably depending on whether the submitted username or email exists in the database. When a user is not found, the server responds immediately. When a user exists but the password is wrong, a bcrypt comparison runs first, adding significant latency. This timing difference allows an unauthenticated attacker to enumerate valid usernames. This vulnerability is fixed in 9.8.0-alpha.6 and 8.6.74.
- CVSS 4.0
- 6.3 MEDIUMCVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.23% probability · 14th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-208
- Affected
- parseplatform/parse-server
- Source
- security-advisories@github.com
References
- https://github.com/parse-community/parse-server/pull/10398Issue Tracking, Patch
- https://github.com/parse-community/parse-server/pull/10399Issue Tracking, Patch
- https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2vMitigation, Patch, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.