CVE-2026-20139VulnerabilityPublished 18 Feb 2026Updated 19 Feb 2026

CVE-2026-20139: Splunk Enterprise · The software does not properly control the allocation and maintenance of a limited resource thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affects Splunk EnterpriseSource CVE Database V5

Not known to be exploited · CVSS 4.3 Medium · fixed in 10.0.2 : update Splunk Enterprise when convenient.

Data as of 25 Oct 2026, 19:02 UTC

CVSS 3.1 base score

4.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 5.6% chance of exploitation in 30 days – higher than 92% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 10.0.2, 9.4.8, 9.3.9 +5

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-25.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade Splunk to 10.0.2, 9.4.8, 9.3.9 or 9.2.12 (Enterprise); 10.2.2510.3, 10.1.2507.8, 10.0.2503.9 or 9.3.2411.121 (Cloud Platform).

Affected software

Product	Affected	Fixed in
SplunkSplunk Enterprise	Affected >=10.0 <10.0.2 >=9.4 <9.4.8 >=9.3 <9.3.9 >=9.2 <9.2.12	Fixed in 10.0.2 9.4.8 9.3.9 9.2.12
SplunkSplunk Cloud Platform	Affected >=10.2.2510 <10.2.2510.3 >=10.1.2507 <10.1.2507.8 >=10.0.2503 <10.0.2503.9 >=9.3.2411 <9.3.2411.121	Fixed in 10.2.2510.3 10.1.2507.8 10.0.2503.9 9.3.2411.121

AI-suggested

1. 2. Restrict access to the password change REST API endpoint to only trusted users and monitor usage patterns for anomalies. 3. Implement strict input validation and sanitization on user attribute fields (`realname`, `tz`, `email`) to prevent injection of malicious payloads. 4. Enforce the principle of least privilege by limiting the number of users with password change capabilities and regularly reviewing role assignments. 5. Monitor Splunk Web performance metrics and logs for signs of resource exhaustion or unusual slowdowns that could indicate exploitation attempts. 6. Consider network segmentation and access controls to limit exposure of Splunk Web interfaces to only necessary internal networks. 7. Educate administrators and users about the risks of resource exhaustion attacks and encourage prompt reporting of interface performance issues. 8. Maintain up-to-date backups and incident response plans to quickly recover from potential denial-of-service conditions.

Description

In Splunk Enterprise versions below 10.2.0, 10.0.2, 9.4.8, 9.3.9, and 9.2.12, and Splunk Cloud Platform versions below 10.2.2510.3, 10.1.2507.8, 10.0.2503.9, and 9.3.2411.121, a low-privileged user that does not hold the "admin" or "power" Splunk roles could craft a malicious payload into the `realname`, `tz`, or `email` parameters of the `/splunkd/__raw/services/authentication/users/username` REST API endpoint when they change a password. This could potentially lead to a client‑side denial‑of‑service (DoS). The malicious payload might significantly slow page load times or render Splunk Web temporarily unresponsive.

Impact

For European organizations relying on Splunk Enterprise or Splunk Cloud Platform for log management, security monitoring, or operational intelligence, this vulnerability could disrupt normal operations by degrading the responsiveness of the Splunk Web interface. Although it does not compromise data confidentiality or integrity, availability issues can delay incident response, log analysis, and other critical security functions. Organizations with many low-privileged users or those that expose Splunk Web interfaces to wider internal or external networks are at higher risk. Temporary denial-of-service conditions could impact security teams’ ability to monitor and react to threats promptly, increasing organizational risk. The impact is primarily operational and could affect compliance with regulatory requirements for continuous monitoring and incident management. However, since exploitation requires authenticated low-privileged access, the threat is somewhat mitigated by strong internal access controls and user management policies.

CWE-400Uncontrolled Resource Consumption (opens in a new tab)
Class weaknessLikelihood of exploit: High
The product does not properly control the allocation and maintenance of a limited resource.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Design throttling mechanisms into the system architecture. The best protection is to limit the amount of resources that an unauthorized user can cause to be expended. A strong authentication and access control model will help prevent such attacks from occurring in the first place.
Architecture and Design
Mitigation of resource exhaustion attacks requires that the target system either: recognizes the attack and denies that user further access for a given amount of time, or; uniformly throttles all requests in order to make it more difficult to consume resources more quickly than they can again be freed.
Architecture and Design
Ensure that protocols have specific limits of scale placed on them.
OWASP Cheat Sheets
File Upload (opens in a new tab)
OWASP ASVS 4.0.3
V12.1.1 (opens in a new tab)
Attack patterns
XML Ping of the Death (opens in a new tab)
Regular Expression Exponential Blowup (opens in a new tab)
Sustained Client Engagement (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

advisory.splunk.com/advisories/SVD-2026-0204 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 19 Feb 2026, 12:10 UTC

WeaknessesCWE-400

Technical details

References

Community reviews

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