CVE-2026-9641
Crypt::PBKDF2 versions before 0.261630 for Perl have a weak default algorithm and number of iterations
- 5.3MediumCVSS base score
- 0.23%Exploitation in 30 daysEPSS · top 87% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
Crypt::PBKDF2 versions before 0.261630 for Perl have a weak default algorithm and number of iterations. The default algorithm is HMAC-SHA1, which should only be used for legacy systems. These versions default to using 1000 iterations. Depending on the chosen algorithm, 220,000 to 1,400,000 iterations should be used.
Timeline
ID reserved
By CPANSec
- 17 days later
· 17 days later
Published
- 2 days later
· 2 days later
Record updated
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 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.23% · top 87% of all CVEs (11 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.3.
Affected products
- affected < 0.261630
What to do
Solution: Upgrade to version 0.261630 or later.
Workaround: Change the default algorithm to something stronger, such as "HMACSHA2", and the output_len accordingly (32 for SHA256). The number of iterations should also be increased (600,000 for SHA256, for example).
References
7
- https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html#pbkdf2 (opens in a new tab)technical-description
- https://metacpan.org/release/ARODLAND/Crypt-PBKDF2-0.261630/changes (opens in a new tab)release-notes
- http://www.openwall.com/lists/oss-security/2026/06/12/5 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/06/13/1 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/06/14/1 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/06/14/2 (opens in a new tab)
- http://www.openwall.com/lists/oss-security/2026/06/14/3 (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-2026-36470 (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-2026-9641)Record last updated .