CVE-2026-20253 | Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise

Exp

In Splunk Enterprise 10.2 versions below 10.2.4 and 10 versions below 10.0.7, an unauthenticated user could create or truncate arbitrary files through a PostgreSQL sidecar service endpoint. The vulnerability exists because the PostgreSQL sidecar service endpoint lacks authentication controls, allowing any network-reachable user to invoke file operations without credentials. Splunk Enterprise versions 9.4 and earlier are not affected. If you cannot immediately upgrade to a fixed version, you can mitigate this vulnerability by disabling the PostgreSQL sidecar service.

Published: 2026-06-10 Last update: 2026-06-19 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-20253 is rated Critical Active Threat (100/100): CVSS Critical severity, with high exploitation likelihood (EPSS 92.10%, 100th percentile). CISA KEV confirms active exploitation (added 2026-06-18) affecting Splunk / Enterprise. a weakness (CWE-306) Unauthenticated remote administrative access may be possible. EPSS rose +82.07% over the last day, indicating growing attacker interest. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2026-20253

Name: Splunk Enterprise Missing Authentication for Critical Function Vulnerability · CISA KEV detail

Exploit added: 2026-06-18

Action due: 2026-06-21

Required action: Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Public exploit references (Exploit-DB) for CVE-2026-20253

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2026-20253

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-23 10.04% 92.10% +82.07%
2 2026-06-19 1.68% 10.04% +8.35%
3 2026-06-15 — 1.68% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-20253

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]

Weakness enumeration for CVE-2026-20253

GitHub Security Advisory for CVE-2026-20253

GHSA-xgm5-jh99-wc4v · Severity: critical — In Splunk Enterprise versions below 10.2.4 and 10.0.7, and Splunk Cloud Platform versions below...

Affected software / configurations for CVE-2026-20253

Vendor Product Version Raw CPE
splunk splunk >= 10.0.0, < 10.0.7 cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*
splunk splunk >= 10.2.0, < 10.2.4 cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*

References for CVE-2026-20253

cvelogic Threat Intelligence