GHSA-hrqr-hxpp-chr3 · Severity: medium · Ecosystem: rubygems — Possible Information Leak / Session Hijack Vulnerability in Rack
There's a possible information leak / session hijack vulnerability in Rack (RubyGem rack). This vulnerability is patched in versions 1.6.12 and 2.0.8. Attackers may be able to find and hijack sessions by using timing attacks targeting the session id. Session ids are usually stored and indexed in a database that uses some kind of scheme for speeding up lookups of that session id. By carefully measuring the amount of time it takes to look up a session, an attacker may be able to find a valid session id and hijack the session. The session id itself may be generated randomly, but the way the session is indexed by the backing store does not use a secure comparison.
Conclusion & alert: CVE-2019-16782 is rated Moderate Risk (58.9/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 3.69%). Core evidence: EPSS rose +2.79% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.89% | 3.69% | +2.79% |
| 2 | 2026-04-20 | 1.25% | 0.89% | -0.36% |
| 3 | 2026-03-26 | — | 1.25% | — |
Full EPSS history (46 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.3 | 3.1 | MEDIUM |
|
1.8 | 4.0 | [email protected] |
| 5.9 | 3.1 | MEDIUM |
|
2.2 | 3.6 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
GHSA-hrqr-hxpp-chr3 · Severity: medium · Ecosystem: rubygems — Possible Information Leak / Session Hijack Vulnerability in Rack
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2019-16782 not yet assigned priority: Debian including 1 source packages (ruby-rack), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2019-16782 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2019-16782 |
suse
|
medium | — | https://www.suse.com/security/cve/CVE-2019-16782/ |
ubuntu
|
medium | CVE-2019-16782 medium priority: Ubuntu including 1 source packages (ruby-rack), 17 status rows across 17 suites (bionic, disco, eoan, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): not-affected 10, released 5, ignored 2. | https://ubuntu.com/security/CVE-2019-16782 |
| URL | Tags |
|---|---|
| http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00016.html | Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2019/12/18/2 | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2019/12/18/3 | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2019/12/19/3 | Mailing List Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2020/04/08/1 | Mailing List Patch Third Party Advisory |
| http://www.openwall.com/lists/oss-security/2020/04/09/2 | Mailing List Third Party Advisory |
| https://github.com/rack/rack/commit/7fecaee81f59926b6e1913511c90650e76673b38 | Patch Third Party Advisory |
| https://github.com/rack/rack/security/advisories/GHSA-hrqr-hxpp-chr3 | Third Party Advisory |
| https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HZXMWILCICQLA2BYSP6I2CRMUG53YBLX/ |