Commvault CommServe is widely deployed enterprise backup software; a high-severity heap overflow can disrupt backups and business continuity, so broad IT notice is warranted.
CVE-2026-77102
Heap buffer overflow in Commvault CommServe causing service crash/DoS
Is CVE-2026-77102 being exploited?
Not confirmed. CVE-2026-77102 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.27% probability of exploitation in the next 30 days.
How severe is CVE-2026-77102?
CVE-2026-77102 is rated High with a CVSS score of 8.7. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-77102?
Yes. A fix has been recorded for CVE-2026-77102. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-77102 affect?
CVE-2026-77102 affects Commvault CommServe. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-77102?
Apply the Commvault CommServe maintenance release from the vendor advisory immediately.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote heap overflow in CommServe can crash the service (DoS); may enable code execution in some conditions.
Immediate action required
- affected>= 11.46.0 and <= 11.46.19
- affected>= 11.44.0 and <= 11.44.19
- affected>= 11.40.0 and <= 11.40.71
- affected>= 11.36.0 and <= 11.36.122
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.