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.
Metrics
Affected Vendors & Products
References
History
Wed, 30 Sep 2026 16:30:00 +0000
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ssvc
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Tue, 29 Sep 2026 06:30:00 +0000
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Browserify
Browserify pbkdf2 |
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| Vendors & Products |
Browserify
Browserify pbkdf2 |
Tue, 29 Sep 2026 04:00:00 +0000
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| 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. | |
| Title | pbkdf2 rehashes long passwords on every iteration, enabling denial of service | |
| Weaknesses | CWE-400 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: harborist
Published: 2026-09-29T03:42:04.950Z
Updated: 2026-09-30T15:17:17.598Z
Reserved: 2026-09-29T02:06:16.561Z
Link: CVE-2026-102414
Updated: 2026-09-30T15:17:00.611Z
Status : Deferred
Published: 2026-09-29T04:17:55.180
Modified: 2026-09-30T17:32:07.107
Link: CVE-2026-102414
No data.