Exploited vulnerabilities / CVE-2026-20253
Confirmed exploited · authentication bypass · Splunk EnterpriseCVE-2026-20253
Splunk Enterprise authentication bypass, confirmed exploited in the wild.
Splunk Enterprise contains a missing authentication for critical function vulnerability which could allow an unauthenticated user to create or truncate arbitrary files through a PostgreSQL sidecar service endpoint.
| CISA's name for it | Splunk Enterprise Missing Authentication for Critical Function Vulnerability |
|---|---|
| Vendor and product | Splunk · Enterprise |
| Type | authentication bypass · CWE-306 |
| Exploited | Confirmed by CISA listed 18 June 2026 |
| Likelihood | one of the most likely to be exploited of every vulnerability tracked |
| Deadline | 21 June 2026 · already passed |
| Used in ransomware | Not reported |
| Advisories | advisory.splunk.com ↗ · www.cisa.gov ↗ · www.cisa.gov ↗ · nvd.nist.gov ↗ |
Three steps, in this order
Apply the vendor fix and restart the affected service.
Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant.
Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.
| CISA's 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. |
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CVE-2026-20253 in short
Is CVE-2026-20253 being exploited?
Yes. CISA added CVE-2026-20253 to its Known Exploited Vulnerabilities catalogue on 18 June 2026, which it does only on evidence of exploitation in the wild.
What is the CISA deadline for CVE-2026-20253?
US federal agencies must remediate it by 21 June 2026. Everyone else should treat that date as the latest safe point to patch an internet-facing system.
How likely is CVE-2026-20253 to be exploited in the next 30 days?
FIRST's Exploit Prediction Scoring System gives it 97%, the 99th percentile of every CVE it scores.
How do I fix CVE-2026-20253?
Apply the vendor fix and restart the affected service. Put the login or management interface behind a VPN or allow-list; a bypass makes passwords irrelevant. Rotate credentials and session keys the product holds, and review accounts and configuration changes since the listing date.
Sources: CISA Known Exploited Vulnerabilities catalogue (released 10 November 2026) and FIRST EPSS. Page compiled automatically by SAK T.L.M, the threat-intelligence tool of SAK T.E.C, on 13 November 2026.