# CVE-2026-77100: Commvault MediaAgent heap buffer overflow denial of service

Source: https://junglewise.ai/threats/cve-2026-77100-mediaagent-contained-a-heap-based-buffer-overflow-issue-affecting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-13. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-77100 · Severity: info · Published 2026-10-13

Commvault MediaAgent, a backup and recovery component, contains a heap buffer overflow that can crash the service and disrupt backup operations. An attacker can exploit this vulnerability to cause a denial of service, potentially preventing organizations from completing critical backups and recovery tasks. Upgrading to the patched maintenance releases resolves the issue.

Vendors: [Commvault](https://junglewise.ai/threats/vendors/commvault).

## Quick answers

**Is CVE-2026-77100 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-77100 being exploited in the wild.

**How severe is CVE-2026-77100?** Informational severity, published 13 October 2026.

**Which products and versions are affected?** Commvault HyperScale 11.46.0-11.46.29, 11.44.0-11.44.24, 11.40.0-11.40.77, 11.36.0-11.36.126; Commvault MediaAgent 11.46.0-11.46.29, 11.44.0-11.44.24, 11.40.0-11.40.77, 11.36.0-11.36.126.

**Is there a fix for CVE-2026-77100?** Yes: fixed in MediaAgent and HyperScale: 11.46.30 and higher, 11.44.25 and higher, 11.40.78 and higher, 11.36.127 and higher. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-77100 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2026-77100?** Check whether you run Commvault HyperScale or Commvault MediaAgent at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in MediaAgent and HyperScale: 11.46.30 and higher, 11.44.25 and higher, 11.40.78 and higher, 11.36.127 and higher

## Technical details

A heap-based buffer overflow in Commvault MediaAgent allows remote exploitation to trigger a denial of service condition. The vulnerability affects multiple maintained versions across Linux and Windows platforms. Patch updates are available for all affected versions: 11.46.30+, 11.44.25+, 11.40.78+, and 11.36.127+.

## Affected products

- Commvault MediaAgent 11.46.0-11.46.29, 11.44.0-11.44.24, 11.40.0-11.40.77, 11.36.0-11.36.126
- Commvault HyperScale 11.46.0-11.46.29, 11.44.0-11.44.24, 11.40.0-11.40.77, 11.36.0-11.36.126

## Timeline

- 2026-10-13: disclosed

## References

- [https://documentation.commvault.com/securityadvisories/CV_2026_10_6.html](https://documentation.commvault.com/securityadvisories/CV_2026_10_6.html)