CVE-2026-84458

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

0.35% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 29.0% of scored records. A rank, not a probability.

NVD base score

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

NVD CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/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

Deferred. NVD last modified this record on 2026-09-28.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

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

2026-09-25 18:15Z1 MO AGO

Last updated

2026-09-25 19:05Z1 MO AGO

Reserved

2026-09-01

Assigning CNA

GitHub_M

Record state

PUBLISHED

Severity

Critical (CVSS 9.1)

CNA CVSS vector

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

Weaknesses

• CWE-287Improper AuthenticationClass

Data version

5.2

Document digest

09efb9a7346e6585266c12b89e651a42d21daa7871187c091a7cae89acd2d5e1

• github.comhttps://github.com/zammad/zammad/security/advisories/GHSA-86cc-3ggh-mf2mx_refsource_CONFIRM
• github.comhttps://github.com/zammad/zammad/commit/0dba387df8e2b46956907975034cd44e4d021b1cx_refsource_MISC