What is CVE-2026-77709?

CVE-2026-77709 is a medium-severity vulnerability in SonicWall Sonicos, classified under Heap-based Buffer Overflow. CVSS score: 5.9/10. Published 2026-11-06.

How severe is CVE-2026-77709?

Medium severity. CVSS v3 base score is 5.9 out of 10.

Buffer overflow in SonicWall Sonicos

CVE-2026-77709

A pre-authentication heap-based buffer overflow vulnerability has been identified in the SonicOS TACACS+ authentication client, which in specific conditions could potentially enable a remote unauthenticated attacker to cause an application level denial of service.

Vulnerability class: Buffer Overflow

Published 2026-11-06 · last modified 2026-11-06.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

SonicWall Sonicos — versions 7.3.3-7015 and older versions, 8.2.2-8015 and older versions

Weakness classification (CWE)

CWE-122 — Heap-based Buffer Overflow

References

psirt.global.sonicwall.com/vuln-detail/SNWLID-2026-0014 (vendor-advisory)

Frequently asked questions

What is CVE-2026-77709?: CVE-2026-77709 is a medium-severity vulnerability in SonicWall Sonicos, classified under Heap-based Buffer Overflow. CVSS score: 5.9/10. Published 2026-11-06.
How severe is CVE-2026-77709?: Medium severity. CVSS v3 base score is 5.9 out of 10.