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    2 vulnerabilities found for bcrypt-ruby by bcrypt-ruby_project

    CVE-2026-33306 (GCVE-0-2026-33306)

    Vulnerability from nvd – Published: 2026-03-24 00:08 – Updated: 2026-03-24 15:39
    VLAI
    Title
    bcrypt-ruby has an Integer Overflow that Causes Zero Key-Strengthening Iterations at Cost=31 on JRuby
    Summary
    bcrypt-ruby is a Ruby binding for the OpenBSD bcrypt() password hashing algorithm. Prior to version 3.1.22, an integer overflow in the Java BCrypt implementation for JRuby can cause zero iterations in the strengthening loop. Impacted applications must be setting the cost to 31 to see this happen. The JRuby implementation of bcrypt-ruby (`BCrypt.java`) computes the key-strengthening round count as a signed 32-bit integer. When `cost=31` (the maximum allowed by the gem), signed integer overflow causes the round count to become negative, and the strengthening loop executes **zero iterations**. This collapses bcrypt from 2^31 rounds of exponential key-strengthening to effectively constant-time computation — only the initial EksBlowfish key setup and final 64x encryption phase remain. The resulting hash looks valid (`$2a$31$...`) and verifies correctly via `checkpw`, making the weakness invisible to the application. This issue is triggered only when cost=31 is used or when verifying a `$2a$31$` hash. This problem has been fixed in version 3.1.22. As a workaround, set the cost to something less than 31.
    Severity
    4.5 (Medium)
    CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: partial
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-190 - Integer Overflow or Wraparound
    Assigner
    References
    Impacted products
    Vendor Product Version
    bcrypt-ruby bcrypt-ruby Affected: < 3.1.22
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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    CVE-2026-33306 (GCVE-0-2026-33306)

    Vulnerability from cvelistv5 – Published: 2026-03-24 00:08 – Updated: 2026-03-24 15:39
    VLAI
    Title
    bcrypt-ruby has an Integer Overflow that Causes Zero Key-Strengthening Iterations at Cost=31 on JRuby
    Summary
    bcrypt-ruby is a Ruby binding for the OpenBSD bcrypt() password hashing algorithm. Prior to version 3.1.22, an integer overflow in the Java BCrypt implementation for JRuby can cause zero iterations in the strengthening loop. Impacted applications must be setting the cost to 31 to see this happen. The JRuby implementation of bcrypt-ruby (`BCrypt.java`) computes the key-strengthening round count as a signed 32-bit integer. When `cost=31` (the maximum allowed by the gem), signed integer overflow causes the round count to become negative, and the strengthening loop executes **zero iterations**. This collapses bcrypt from 2^31 rounds of exponential key-strengthening to effectively constant-time computation — only the initial EksBlowfish key setup and final 64x encryption phase remain. The resulting hash looks valid (`$2a$31$...`) and verifies correctly via `checkpw`, making the weakness invisible to the application. This issue is triggered only when cost=31 is used or when verifying a `$2a$31$` hash. This problem has been fixed in version 3.1.22. As a workaround, set the cost to something less than 31.
    Severity
    4.5 (Medium)
    CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U
    SSVC
    Exploitation: none Automatable: no Technical Impact: partial
    CISA Coordinator (v2.0.3)
    CWE
    • CWE-190 - Integer Overflow or Wraparound
    Assigner
    References
    Impacted products
    Vendor Product Version
    bcrypt-ruby bcrypt-ruby Affected: < 3.1.22
    		Create a notification for this product.
    Show details on NVD website
    To clipboard 

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