NULL pointer dereference in Wireshark

CVE-2025-9817

SSH dissector crash in Wireshark 4.4.0 to 4.4.8 allows denial of service

EPSS: 0.002 (9.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Wireshark — versions 4.4.9
Wireshark Foundation — versions 4.4.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

cve@gitlab.com (Third Party Advisory)
cve@gitlab.com (issue-tracking, permissions-required, Issue Tracking)

Frequently asked questions

What is CVE-2025-9817?: CVE-2025-9817 is a high-severity vulnerability in Wireshark, classified under NULL Pointer Dereference. CVSS score: 7.8/10. Published 2025-09-03.
How severe is CVE-2025-9817?: High severity. CVSS v3 base score is 7.8 out of 10.
Is CVE-2025-9817 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.