CVE-2026-76300: 
Splunk Enterprise vulnerability analysis and mitigation

CVE-2026-76300 is a vulnerability in Splunk Enterprise related to improper control of a resource through its lifetime (CWE-664), discovered as part of Cisco's internal security review and addressed in a software hardening release. It affects Splunk Enterprise versions 9.4.x before 9.4.16, 10.0.x before 10.0.11, 10.2.x before 10.2.8, and 10.4.x before 10.4.4. The vulnerability was published on October 21, 2026, with patches made available the same day. The CVSS category is estimated as High, though a precise numeric score has not been published at this time (GitHub Advisory, Feedly).

The vulnerability is classified under CWE-664 (Improper Control of a Resource Through its Lifetime), meaning the software does not correctly maintain control over a resource during its creation, use, or release phases. Associated CAPEC patterns include session credential falsification (CAPEC-196), exploitation of trusted identifiers (CAPEC-21), session replay (CAPEC-60), session fixation (CAPEC-61), and cross-site request forgery (CAPEC-62), suggesting the resource lifecycle issue may relate to session or token management. The MITRE ATT&CK mappings (T1134 – Access Token Manipulation, T1550.004 – Web Session Cookie) further indicate that improper resource handling could be leveraged to manipulate authentication tokens or session cookies (GitHub Advisory, Feedly).

Successful exploitation of CVE-2026-76300 could allow an unauthenticated attacker or local user to trigger denial of service, resource exhaustion, or other adverse effects stemming from uncontrolled resource lifecycle management within Splunk Enterprise. Given the CAPEC and ATT&CK mappings, there is also potential for session or token abuse, which could lead to unauthorized access or privilege escalation within the Splunk environment. The full scope of confidentiality, integrity, and availability impacts has not been fully detailed in public disclosures at this time (Feedly).

There is no evidence of public proof-of-concept exploit code or active in-the-wild exploitation of CVE-2026-76300 as of the time of disclosure. The EPSS score is reported as 0.0, and the vulnerability has not been added to the CISA Known Exploited Vulnerabilities (KEV) catalog. The vulnerability was identified through Cisco's internal security review rather than external researcher discovery, suggesting it has not yet been weaponized (GitHub Advisory, Feedly).

Splunk has released patched versions addressing CVE-2026-76300. Organizations should upgrade Splunk Enterprise to one of the following fixed versions as soon as possible:

• 9.4.x: Upgrade to 9.4.16 or later
• 10.0.x: Upgrade to 10.0.11 or later
• 10.2.x: Upgrade to 10.2.8 or later
• 10.4.x: Upgrade to 10.4.4 or later

No specific configuration-based workarounds have been published. Organizations should consult the official Splunk advisory (SVD-2026-1008) for additional guidance (Splunk Advisory, GitHub Advisory).