CVE-2026-39324

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
• Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.27% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 18.9% of scored records. A rank, not a probability.

NVD base score

9.3 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

NVD analysis status

Analyzed. NVD last modified this record on 2026-10-26.

Red Hat severity

Critical. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-04-07 18:13Z6 MO AGO

Last updated

2026-04-08 18:44Z6 MO AGO

Reserved

2026-04-06

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Critical (CVSS 9.3)

CNA CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-287Improper AuthenticationClass
• CWE-345Insufficient Verification of Data AuthenticityClass
• CWE-502Deserialization of Untrusted DataBase
• CWE-565Reliance on Cookies without Validation and Integrity CheckingBase

Data version

5.2

Document digest

4abbd95792bb360b24ae48d9bdba8bce09fa90e1f310f2db3b838d8191e4428a

• github.comhttps://github.com/rack/rack-session/security/advisories/GHSA-33qg-7wpp-89cqx_refsource_CONFIRM