Description
JRuby before 1.6.5.1 computes hash values without restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | jruby | 1.5.6-4 | — |
| Debian 13 | jruby | 1.5.6-4 | — |
| Debian 12 | jruby | 1.5.6-4 | — |
| Debian 6.0 | jruby | 1.5.1-1+deb6u1 | DLA-209-1 |
Advisories 1
- DLA-209-1 jruby - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- http://www.nruns.com/_downloads/advisory28122011.pdf
- jruby-hash-dos(72019) vdb-entry
- http://jruby.org/2011/12/27/jruby-1-6-5-1.html
- 50084 third-party-advisory
- 47407 third-party-advisory
- VU#903934 third-party-advisory
- RHSA-2012:1232 vendor-advisory
- 20111228 n.runs-SA-2011.004 - web programming languages and platforms - DoS through hash table mailing-list
- GLSA-201207-06 vendor-advisory
- http://www.ocert.org/advisories/ocert-2011-003.html