CVE-2026-76277 Improper Input Validation of Native Splunk Usernames through the REST API in Splunk Enterprise
Attackers with edit_user capability can create usernames ending in periods, causing configuration data sharing and affecting wrong accounts.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-76277?
CVE-2026-76277 is a medium-severity vulnerability in Splunk Splunk, published on 7 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
In Splunk Enterprise versions below 10.4.3, 10.2.7, 10.0.10, and 9.4.15, a user that holds a role with the edit_user capability could create a native Splunk username that ends with a period. The vulnerability is possible because username validation does not reject a trailing period before the username is used for a user directory. This can cause distinct native Splunk usernames to share per-user configuration data, and user-management operations can affect the wrong account or fail. For more information see Set up native Splunk authentication (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.4/use-the-native-splunk-platform-authentication-scheme/set-up-native-splunk-authentication) and Define roles on the Splunk platform with capabilities (https://help.splunk.com/en/splunk-enterprise/administer/manage-users-and-security/10.4/manage-splunk-platform-users-and-roles/define-roles-on-the-splunk-platform-with-capabilities) in the Splunk documentation.
Weakness: CWE-20
Which versions are affected by CVE-2026-76277?
It affects 1 product.
Products include Splunk Splunk.
How do I fix CVE-2026-76277?
No fix has been published for CVE-2026-76277 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-76277 being exploited?
There is no known exploitation of CVE-2026-76277 in the wild and no public exploit code.
Other vulnerabilities in Splunk Splunk
- CVE-2026-20253 Splunk Enterprise Missing Authentication for Critical Function
- CVE-2026-76268 Missing Authentication for Critical Function in the Patroni REST API in Splunk Enterprise
- CVE-2026-76284 Improper Neutralization in Splunk Enterprise
- CVE-2026-76285 Improper Adherence to Coding Standards in Splunk Enterprise
- CVE-2017-17067 Auth bypass in n/a
Sources
Also known as GHSA-f49j-g49x-qqr9.