CASCACascade Atlas

Evidence dossier

CVE-2026-20253

Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise

83.3–98.3Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

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.

State
PUBLISHED
Published
Jun 10, 2026
Updated
Jun 19, 2026
Evidence coverage
85%
CISA KEVCatalog member

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.

FIRST EPSS88.17%

2026-07-18 · v2026.06.15 · percentile 99.8%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

ciscooriginal assertion
container

Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise

CISA KEVoriginal assertion
observed_exploitation

Splunk Enterprise Missing Authentication for Critical Function Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.881710000000; percentile 0.997510000000

Applicability

Cited product scope

Trace impact →
SplunkSplunk Enterprise
[{"status": "affected", "version": "10.2", "lessThan": "10.2.4", "versionType": "custom"}, {"status": "affected", "version": "10.0", "lessThan": "10.0.7", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*; start including 10.0.0; end excluding 10.0.7supported
Unknown vendorUnknown product
cpe:2.3:a:splunk:splunk:*:*:*:*:enterprise:*:*:*; start including 10.2.0; end excluding 10.2.4supported

Assessments

CVSS by origin

9.8
psirt@cisco.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
ciscoCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.