Buffer overflow in Commvault

CVE-2026-77101

CommServe contained a stack-based buffer overflow issue affecting service availability. Software customers upgrade to resolved maintenance release. Update CommServe.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.005 (38.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 39th percentile — 38.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-77101: held from 0.003 to 0.005.

EPSS over last 30 days · oldest: 0.003 · newest: 0.005 · change: +0.002

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-77101?
CVE-2026-77101 is a high-severity vulnerability in Commvault, classified under Stack-based Buffer Overflow. CVSS score: 7.5/10. Published 2026-09-08.
How severe is CVE-2026-77101?
High severity. CVSS v3 base score is 7.5 out of 10.