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CVE-2026-20253

CRITICAL 9.8 KNOWN EXPLOITED PoC CATALOGUED DETECTION TEMPLATE ALL-YEARS

Published 2026-06-10 · Last modified 2026-06-19 · cisco · NVD: Analyzed

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.

ACTIVELY EXPLOITED

Confirmed exploited in the wild — in CISA KEV since 2026-06-18. Patch or mitigate now.

Exploitation likelihood

96.9%chance of exploitation in 30 days · 100th percentile

● In CISA KEV (2026-06-18)● Catalogued PoC◆ SSVC: exploitation active, automatable yes

Impact if exploited

9.8CVSS 3.1 · CRITICAL · CNA

  • ConfidentialityHigh
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

Public PoC or exploit resources are catalogued below.

Listed by the named source; Vulnpedia has not tested these resources.

PoC data: JSON

Detection templates

Detection checks are listed separately from PoCs.

Resource commands

nuclei -id CVE-2026-20253 -u https://TARGETDetection template — review its checks and affected versions before use.
curl -s https://vulnpedia.com/cve/CVE-2026-20253/poc.jsonMachine-readable PoC index for this CVE (for automation).

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors Splunk

Products Splunk Enterprise Splunk

Weakness (CWE)

  • CWE-306: The software does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.

CVSS vector

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

References and research data (JSON)

Unverified PoC candidates

Catalogue matches for further research. These repositories have not been validated as working exploits.

7 candidates

Additional exploitation reports

Source-specific reports, separate from CISA KEV. Repeated observations from one source are not independent confirmations.

50 more source reports

Known Affected Software Configurations

VendorProductVersion range
SplunkSplunk≥ 10.0.0 and < 10.0.7
SplunkSplunk≥ 10.2.0 and < 10.2.4

All CVSS metrics

  • CRITICAL 9.8 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • CRITICAL 9.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Exploit-tagged references (not proof of a PoC)

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · All sources and attribution · EPSS