Live Exposure Defense: From CVE to Confirmed Exposure in 12 Hours – See more

Back
New CVE Detected

CVE-2026-77101 – Denial of Service (Stack-Based Buffer Overflow) – Commvault CommServe (Multiple Mai

Be the first to know when new zero-days emerge:

Subscribe to Email Alerts
Subscribe to RSS Feed

Summary

CVE-2026-77101 is a stack-based buffer overflow (CWE-121) in the CommServe component of Commvault Cloud that affects service availability. The flaw impacts multiple maintenance release lines of Commvault on both Windows and Linux, and carries a High severity rating of 8.7. Commvault has published fixed maintenance releases for all affected version lines.

Technical details

  • Root cause: A stack-based buffer overflow condition exists in the CommServe component of Commvault Cloud.
  • Attack vector: Network (AV:N), requiring no privileges (PR:N) and no user interaction (UI:N), with low attack complexity (AC:L).
  • Trigger conditions: The vendor advisory does not disclose the specific request or code path that triggers the overflow.
  • Impact: The CVSS vector indicates high impact to availability (VA:H) only, with no confidentiality or integrity impact documented — consistent with the vendor’s description of the issue as affecting "service availability."

Affected software

  • Commvault Cloud 11.46.0 through 11.46.19 (fixed in 11.46.20)
  • Commvault Cloud 11.44.0 through 11.44.19 (fixed in 11.44.20)
  • Commvault Cloud 11.40.0 through 11.40.71 (fixed in 11.40.72)
  • Commvault Cloud 11.36.0 through 11.36.122 (fixed in 11.36.123)
  • Affects both Windows and Linux platforms

Severity

  • CVSS v4.0 Base Score: 8.7 (High)
  • Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Mitigation and recommended actions

  • Immediate: Upgrade CommServe to the applicable resolved maintenance release for your deployment: 11.46.20+, 11.44.20+, 11.40.72+, or 11.36.123+.
  • If no patch can be applied immediately: Commvault’s advisory does not document any interim workaround; upgrading to a fixed maintenance release is the only remediation path provided by the vendor.

How IONIX identifies potentially affected assets

IONIX matches the following signals against data already collected when it crawled the asset; identifying the technology sends no request beyond that crawl.

  • Server response header: Commvault WebServer
  • Asset URL path: /webconsole/login/index.jsp

References

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report

How IONIX’s External Exposure Management Platform Detects and Validates
Zero-Days to Shrink MTTR

1

Map your entire attack surface (continously)

IONIX uses multi-factor discovery methods, including DNS analysis, certificate mapping, metadata inspection, and more, to automatically map every internet-facing asset across your environment. This includes cloud instances, third-party platforms, shadow IT, and even forgotten infrastructure that traditional tools miss.

2

Monitor for new CVEs

Dozens of threat intel feeds using agentic technology are continuously analyzed to detect the appearance of proof-of-concept code, exploit kits, and indicators of active targeting. IONIX goes further by applying AI to proactively evaluate whether emerging vulnerabilities are likely to be exploited, even before PoCs go public.

3

Identify Potential External Exposures

Not all CVEs matter. IONIX filters vulnerabilities by asking attacker-centric questions: Can it be reached from the internet? Does it require authentication? Is it being exploited in the wild? This dramatically reduces noise and focuses teams on threats that can actually be weaponized.

4

Create Safe, Scalable Exploit Validations

IONIX transforms real-world PoCs into safe, non-intrusive test payloads that can be run in production environments without disruption. These simulations are precisely targeted to the systems that are vulnerable, ensuring rapid validation without unnecessary load.

5

Execute Exploit Validations

By combining context about software stack, versioning, exposure status, and reachability, IONIX ensures that only the right payloads are executed against the right assets, maximizing efficiency and minimizing risk.

6

Drive Fast and Actionable Remediation

Results are routed through integrations with ticketing, SOAR, and SIEM tools. Issues are written in plain language, bundled into remediation clusters, and prioritized based on asset criticality, exploitability, and blast radius. This shortens mean time to remediation (MTTR) and empowers teams to act with confidence.

Are you exposed?

Get a free report of your organization’s exposure to this CVE and threat

  • Mapping of all Assets with this Technology
  • Identification of potentially exposed assets to this CVE
  • Confirmation of verified exploitable assets
Get Exposure Report
Close

Subscribe to Threat Center RSS

Copy/paste the link below into your preferred RSS reader or follow these instructions to subscribe to Slack alerts.

Open RSS feedSlack setup instructions

Close

Get Real-Time CVE Alerts to Your Email

Be the first to know when new zero-days emerge