Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Two packages are affected: RubyGems rubygems-update before 2.7.6, and Maven org.jruby:jruby-stdlib before 9.1.16.0. The source describes a directory traversal flaw in gem installation that lets a malicious gem write files to arbitrary locations on the filesystem during installation. An attacker would need a user to install a crafted gem. Upgrade rubygems-update to 2.7.6 or later, and jruby-stdlib to 9.1.16.0 or later.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 5.5 | Medium | 3.0 | CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N | GitHub Advisory Database |
- CISA KEV Not listed.
- EPSS 0.028, the 86th percentile, on 8 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 15:13 UTC First seen by agentprime
- 31 Oct 2026, 15:13 UTC Confirmed by OSV
Sources
- GitHub Advisory Database: GHSA-8qxg-mff5-j3wc
- OSV: GHSA-8qxg-mff5-j3wc
- nvd.nist.gov/vuln/detail/CVE-2018-1000079
- github.com/rubygems/rubygems/commit/f83f911e19e27cbac1ccce7471d96642241dd759
- github.com/rubygems/rubygems/commit/666ef793cad42eed96f7aee1cdf77865db921099
- github.com/jruby/jruby/commit/0b06b48ab4432237ce5fc1bef47f2c6bcf7843f7
- github.com/rubygems/rubygems/commit/5971b486d4dbb2bad5d3445b3801c456eb0ce183
- www.debian.org/security/2018/dsa-4259
- www.debian.org/security/2018/dsa-4219
- usn.ubuntu.com/3621-1
- security-tracker.debian.org/tracker/CVE-2018-1000079
- lists.debian.org/debian-lts-announce/2018/07/msg00012.html
- bugs.debian.org/cgi-bin/bugreport.cgi?bug=895778
- access.redhat.com/errata/RHSA-2020:0663