CVE-2026-39324
critical
CVSS v3
—
CVSS v4 NEW
—
VIR risk
9.5
Description
Rack::Session::Cookie secrets: decrypt failure fallback enables secretless session forgery and Marshal deserialization
Predictions
Exploit likelihood
20%
Patch ETA
—
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 3 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 2.1.1-0.2 |
| forky | Fixed | 2.1.1-0.2 |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| RubyGems | rack-session | !< 2.0.0||<>= 2.1.2 | >= 2.1.2 |
| RubyGems | rack-session | >=2.0.0,<2.1.2 | 2.1.2 |
| RUBYGEMS | rack-session | >= 2.0.0, < 2.1.2 | 2.1.2 |
References
- https://github.com/rack/rack-session/security/advisories/GHSA-33qg-7wpp-89cq
- https://www.suse.com/security/cve/CVE-2026-39324.html
- https://nvd.nist.gov/vuln/detail/CVE-2026-39324
- https://github.com/rack/rack-session
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack-session/CVE-2026-39324.yml
- https://security-tracker.debian.org/tracker/CVE-2026-39324
- https://github.com/advisories/GHSA-33qg-7wpp-89cq
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.