SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-102414

pbkdf2 through 3.1.6 re-hashes passwords longer than the digest's block size on every iteration in its JavaScript fallback (lib/sync.js).

MEDIUM 6.3EPSS 0.34%

Does this matter?

Lower severity and a low EPSS score (0.34%). Track it; it rarely justifies an emergency change on its own.

Description

pbkdf2 through 3.1.6 re-hashes passwords longer than the digest's block size on every iteration in its JavaScript fallback (lib/sync.js). A password longer than the block size (64 bytes, or 128 bytes for sha384 and sha512) is passed to HMAC as the key on every iteration, and HMAC hashes such keys in full each time. Cost is therefore O(iterations × password length), and a long password can block the event loop. The fallback is used by pbkdf2Sync and pbkdf2 on Node.js before 0.12, on Bun (1.0.0 through 1.1.34, and 1.2.6 and later), and on Deno 2.9.0 and later, because their native pbkdf2Sync fails the library's feature check. It is also used when lib/sync.js is imported directly. Node.js 0.12 and later, and browser builds (which use lib/sync-browser.js), are not affected. Applications that enforce a reasonable maximum password length are not meaningfully affected.

CVSS 4.0
6.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/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
0.34% probability · 28th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-400
Source
7ffcee3d-2c14-4c3e-b844-86c6a321a158
EPSS trend
0%3%5%29 September 2026: 0.28%26 October 2026: 0.34%29 September 202626 October 2026

EPSS moved from 0.3% on 29 September 2026 to 0.3% on 26 October 2026.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.