Description
JRuby computes hash values without properly 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, as demonstrated by a universal multicollision attack against the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4838.
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 | 1.5.6-5 | — |
| Debian 13 | jruby | 1.5.6-5 | — |
| Debian 12 | jruby | 1.5.6-5 | — |
| Debian 6.0 | jruby | 1.5.1-1+deb6u1 | DLA-209-1 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | org.jruby:jruby-parent | < 1.7.1 | 1.7.1 | GHSA-fmmq-j7pq-f85c |
Advisories 1
- DLA-209-1 jruby - security update Debian Security (DSA / DLA) · Mar 9, 2026
References
- https://bugzilla.redhat.com/show_bug.cgi?id=880671
- http://asfws12.files.wordpress.com/2012/11/asfws2012-jean_philippe_aumasson-martin_bosslet-hash_flooding_dos_reloaded.pdf
- https://www.131002.net/data/talks/appsec12_slides.pdf
- http://2012.appsec-forum.ch/conferences/#c17
- http://www.ocert.org/advisories/ocert-2012-001.html
- RHSA-2013:0533 vendor-advisory