# CVE-2026-20253 — Splunk Enterprise **CISA KEV** > As of 2026-06-19, CVE-2026-20253 is a CRITICAL-severity vulnerability in Splunk Enterprise, CVSS v3.1 9.8, EPSS 88.1% (99.7th percentile). It is listed in the CISA Known Exploited Vulnerabilities catalog (added 2026-06-18), with a US federal remediation deadline of 2026-06-21. Threadlinqs Intelligence links 2 tracked threat campaigns to CVE-2026-20253, most recently “CVE-2026-20253: Unauthenticated Pre-Auth RCE in Splunk Enterprise PostgreSQL Sidecar Service (SVD-2026-0603)”. **Last updated:** 2026-06-19 ## What is CVE-2026-20253? 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. The record classifies CVE-2026-20253 under weakness class [CWE-306](https://cwe.mitre.org/data/definitions/306.html). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 95 days ago. ## Severity and exploitation probability - **CVSS v3.1 base score:** 9.8 — CRITICAL (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`) - **EPSS (FIRST):** 88.1% probability of exploitation in the next 30 days, higher than 99.7% of all scored CVEs - **CISA KEV:** Listed since 2026-06-18, federal remediation deadline 2026-06-21 - **Threadlinqs priority:** 9/10 — CISA KEV-listed, which Threadlinqs floors at 9 - **Published:** 2026-06-10, last modified 2026-06-19 ## Is CVE-2026-20253 being exploited? CISA added CVE-2026-20253 to the Known Exploited Vulnerabilities catalog on 2026-06-18, which means the agency holds evidence of exploitation in the wild; US federal civilian agencies had to remediate it by 2026-06-21 under BOD 22-01. Weaponised exploit code for CVE-2026-20253 is publicly available. 6 public proof-of-concept repositories are tracked for this identifier. A ProjectDiscovery Nuclei detection template exists (`http/cves/2026/CVE-2026-20253.yaml`). It currently carries a trending score of 68 in the Threadlinqs vulnerability feed. - [watchtowrlabs/watchTowr-vs-Splunk-CVE-2026-20253](https://github.com/watchtowrlabs/watchTowr-vs-Splunk-CVE-2026-20253) (github) - [0xBlackash/CVE-2026-20253](https://github.com/0xBlackash/CVE-2026-20253) (github) - [HORKimhab/CVE-2026-20253](https://github.com/HORKimhab/CVE-2026-20253) (github) - [fevar54/CVE-2026-20253-Splunk-Enterprise-Pre-Auth-RCE-](https://github.com/fevar54/CVE-2026-20253-Splunk-Enterprise-Pre-Auth-RCE-) (github) - [pssec-io/CVE-2026-20253](https://github.com/pssec-io/CVE-2026-20253) (github) - [trickest/cve](https://github.com/trickest/cve/blob/main/2026/CVE-2026-20253.md) (trickest) ## Affected products and versions - **Splunk**: Enterprise ## How to fix CVE-2026-20253 Vendor advisory: [https://advisory.splunk.com/advisories/SVD-2026-0603](https://advisory.splunk.com/advisories/SVD-2026-0603). Because CVE-2026-20253 is KEV-listed, US federal civilian agencies were required to apply the vendor fix, or stop using the product, by 2026-06-21. Apply the vendor fix referenced above to every affected product listed in this record, then confirm the running version against the vendor advisory. ## Threat activity tracking CVE-2026-20253 2 tracked threats in the Threadlinqs corpus reference CVE-2026-20253, either in the campaign’s CVE list or as an indicator on the campaign record. - [CVE-2026-20253: Unauthenticated Pre-Auth RCE in Splunk Enterprise PostgreSQL Sidecar Service (SVD-2026-0603)](https://intel.threadlinqs.com/threat/TL-2026-0786) — CRITICAL · 2026-06-13 - [CVE-2026-20253: Critical Unauthenticated Remote Code Execution in Splunk Enterprise via PostgreSQL Sidecar Service](https://intel.threadlinqs.com/threat/TL-2026-1103) — CRITICAL · 2026-06-10 ## Sources Enriched from CVE.org, NVD, FIRST EPSS, CISA KEV, GitHub Security Advisories, public proof-of-concept repositories, ProjectDiscovery Nuclei. Last verified by Threadlinqs on 2026-07-06. This product uses the NVD API but is not endorsed or certified by the NVD. **Other references** - [advisory.splunk.com](https://advisory.splunk.com/advisories/SVD-2026-0603) Canonical: https://intel.threadlinqs.com/cve/CVE-2026-20253 Full detection coverage and IOCs for threats exploiting CVE-2026-20253 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp