- 5.9MediumCVSS base score
- 0.32%Exploitation in 30 daysEPSS · top 75% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Crypt::PBKDF2 versions before 0.261630 for Perl are vulnerable to timing attacks. These versions use Perl's built-in eq comparison. Discrepancies in timing could be used to guess the underlying derived-key.
Timeline
ID reserved
By CPANSec
- 17 days later
· 17 days later
Published
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Medium5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.32% · top 75% of all CVEs (10 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
Loading the EPSS history…
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.9.
Affected products
- affected < 0.261630
What to do
Solution: Upgrade to version 0.261630 or later.
Workaround: Apply the patch from the referenced pull request.
References
4
- https://github.com/arodland/Crypt-PBKDF2/pull/6 (opens in a new tab)issue-tracking
- https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.161520/source/lib/Crypt/PBKDF2.pm#L123-148 (opens in a new tab)
- https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.261630/changes (opens in a new tab)release-notes
- http://www.openwall.com/lists/oss-security/2026/06/12/3 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2017-18978 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2017-20240)Record last updated .