CVE-2026-39321

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

6.3CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

CVSS 3.1

3.7CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 13% of CVEs (scores of 2026-10-26)

CWE

CWE-208

Published

2026-04-07

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

Affected

• parseplatform:parse-server

Packages (OSV)

References

• https://github.com/parse-community/parse-server/pull/10398
• https://github.com/parse-community/parse-server/pull/10399
• https://github.com/parse-community/parse-server/security/advisories/GHSA-mmpq-5hcv-hf2v

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