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HIGH severity

CVE-2026-76259

HIGH

CVE-2026-76259 is a high-severity (CVSS 8.8) Improper Privilege Management vulnerability in splunk splunk. O3 Security detects and blocks CVE-2026-76259 exploitation at runtime via eBPF exploit-chain detection and L7 egress monitoring, even on unpatched systems.

In Splunk Enterprise for Windows versions below 10.4.2, 10.2.6, 10.0.9, 9.4.13, and 9.3.14, a local user with access to the Windows host could bind to the management port before Splunk…

Published
Aug 19, 2026
Updated
Aug 27, 2026
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Sep 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • A successful exploit gives an attacker total control of the affected component, not partial access.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-76259.

EPSS Exploitation Probability

via FIRST.org ↗
0.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs3th percentile — riskier than 3% of all scored CVEsHighest risk
0.00%0.21%0.42%0.63%0.1%0.1%Sep 26Sep 26

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2026-76259 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 368,770 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Description

In Splunk Enterprise for Windows versions below 10.4.2, 10.2.6, 10.0.9, 9.4.13, and 9.3.14, a local user with access to the Windows host could bind to the management port before Splunk Enterprise starts, intercept authentication tokens from child processes, and use those tokens to compromise all relevant data and system integrity available to the user account running Splunk Enterprise. The vulnerability is possible because the Windows management-port listener does not apply exclusive address binding protections before the service starts.

Affected Products

1 product · 5 configurations
Application
splunksplunk
≥ 10.4.0 && < 10.4.2
range

Detection & mitigation playbook

Vendor / appliance
  1. Detect

    Inventory every splunk splunk deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.

  2. Fix

    Apply the splunk splunk security patch or hotfix for CVE-2026-76259 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.

  4. How O3 protects you

    O3 detects and blocks CVE-2026-76259 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.

Tailored to CVE-2026-76259. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In Splunk Enterprise for Windows versions below 10.4.2, 10.2.6, 10.0.9, 9.4.13, and 9.3.14, a local user with access to the Windows host could bind to the management port before Splunk Enterprise starts, intercept authentication tokens from child processes, and use those tokens to compromise all relevant data and system integrity available to the user account running Splunk Enterprise. The vulnerability is possible because the Windows management-port listener does not apply exclusive address binding protections before the service starts.
O3 Security · Runtime Protection

Is CVE-2026-76259 being exploited in your environment?

O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-76259 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.

CVE-2026-76259: SPLUNK Improper Privilege… | O3 Security