Password-hash weakening via predictable salt generation
Published Jun 12, 2026 · Updated Jun 12, 2026
Weak salt generation in Crypt::PBKDF2 before 0.261630 allows attackers to predict salts embedded in generated password hashes. The _random_salt routine fills salt bytes with Perl's built-in rand function, whose output is unsuitable for cryptographic use. Applications that omit an explicit salt invoke the vulnerable path, weakening resistance to precomputed password-guessing attacks.
Summary
What happened
Weak salt generation in Crypt::PBKDF2 before 0.261630 allows attackers to predict salts embedded in generated password hashes. The _random_salt routine fills salt bytes with Perl's built-in rand function, whose output is unsuitable for cryptographic use. Applications that omit an explicit salt invoke the vulnerable path, weakening resistance to precomputed password-guessing attacks.
The record
- CVE
- CVE-2026-9638
- Published
- Jun 12, 2026
- Updated
- Jun 12, 2026
- Vendor
- Andrew Rodland
- Product
- Crypt::PBKDF2
- Classifications
- CWE-338, T1110.002
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 12, 2026CVE publishedPublication date reported by the CVE source.
- Jun 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <0.261630
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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