CVE-2026-20253
Confirmed PUBLISHEDUnauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sidecar Service Endpoint in Splunk Enterprise
3 days faster than CISA KEV
Recommended Action
Prioritize immediate patching and validate internet-facing exposure. Monitor for matching exploitation attempts in your environment.
At a Glance
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.
- CVE Published
- Jun 10, 2026
- Exploited Since
- Jun 12, 2026
- CVSS
- 9.8 Critical
- EPSS
- 96.2%
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Splunk |
Splunk Enterprise
|
10.2 to < 10.2.4 |
Affected |
| Splunk |
Splunk Enterprise
|
10.0 to < 10.0.7 |
Affected |
CVE References
- advisory.splunk.com/advisories/SVD-2026-0603 advisory.splunk.com · CVE Record https://advisory.splunk.com/advisories/SVD-2026-0603
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| KEVIntel First | 2026-06-15 05:15 UTC |
| CISA | 2026-06-18 00:00 UTC |
| CVE | 2026-06-18 17:41 UTC |
| Daily CyberSecurity | 2026-06-18 18:20 UTC |
| All CISA Advisories | 2026-06-18 18:20 UTC |
| The Shadowserver | 2026-07-09 00:00 UTC |
Operational indicators for this CVE are listed on the Detection tab.
Observed Exploitation Attempts
Exploitation attempts against this vulnerability observed first-hand by KEVIntel private honeypots over the last 30 days.
- Attempts Observed
- 605
- Unique Attacker IPs
- 59
- Attacker Countries
- 🇧🇬 🇨🇱 🇨🇳 🇨🇿 🇩🇪 🇪🇸 🇫🇷 🇬🇧 🇭🇰 🇮🇳 🇯🇵 🇰🇷 🇳🇱 🇸🇪 🇸🇬 🇹🇼 🇺🇸 🇻🇳
- Sensors Observed
- 2
Exploitation Attempts Over the Last 52 Days
First observed (all time) 2026-06-12 21:36 UTC · Last observed 2026-07-30 05:16 UTC
See more exploitation detail
- Pro — sensor software/region breakdown and 24h/7d window summaries.
- Enterprise — raw attacker IPs, request paths, User-Agents, and payloads.
Indicators of Compromise (IoCs)
Attacker IP IoCs observed in KEVIntel sensors are available to Pro and Enterprise accounts on the Detection tab and through the Pro API.
Learn about Pro API accessObserved Detection Signals (30d)
Aggregate counts from KEVIntel sensor telemetry for this CVE.
- Distinct request targets
- 15
- Distinct User-Agents
- 28
The specific request targets and User-Agents attackers are using are available on Pro and Enterprise plans.
Scanner Artifacts
Scanner and exploit-framework references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-20253.yaml | Jun 15, 2026 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
Supported Platforms
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
GET /api/v2/enterprise/virtual_patches?cve_id=CVE-2026-20253
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploitation Status
Exploited in the wild
Recorded 2026-06-15 05:15:25 UTC · KEVIntel
Active exploitation observed
Recorded 2026-06-15 05:15:25 UTC · KEVIntel sensor
Proof of concept available
Recorded 2026-06-12 10:04:32 UTC · GitHub
Weaknesses (CWE)
-
Missing Authentication for Critical Function
Scanner Integrations
Nuclei, Metasploit, and other scanner references for this CVE are listed on the Detection tab.
Recent Mentions
Daily CyberSecurity · Jun 18, 2026
The cybersecurity landscape faces a critical threat today. CISA confirmed active exploitation of Splunk CVE-2026-20253. Consequently, administrators The post Splunk CVE-2026-20253: CVSS 9.8 RCE Exploited in the Wild appeared first on Daily CyberSecurity.
All CISA Advisories · Jun 18, 2026
CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-20253 Splunk Enterprise Missing Authentication for Critical Function Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 26-04: Prioritizing Security Updates Based on Risk establishes vulnerability management requirements for Federal Civilian Executive Branch (FCEB) agencies, updating BOD 22-01. BOD 26-04 reinforces the importance of the KEV Catalog and requires federal agencies to prioritize rapid remediation of high-risk vulnerabilities, specifically those identified by Common Vulnerabilities and Exposures (CVEs) listed in CISA’s Known Exploited Vulnerabilities (KEV) Catalog on publicly exposed assets that grant total control of the asset post-exploitation, while deferring action for lower-risk vulnerabilities. BOD 26-04 further establishes basic expectations for when agencies must check whether threat actors compromised the system before the patch was applied. While BOD 26-04 applies only to FCEB agencies, CISA encourages all organizations to adopt risk-based vulnerability management and prioritize remediation of KEV Catalog vulnerabilities. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria. Aware of an exploited vulnerability not currently listed in the KEV Catalog? Submit for potential addition: KEV Nomination Form. Potential KEV additions must have a CVE ID, evidence of exploitation, and clear mitigation guidance.
TheHackerNews · Jun 13, 2026
Splunk has released security updates to address a critical security flaw in Splunk Enterprise that could be exploited to conduct unauthenticated file operations and even remote code execution. The vulnerability, tracked as CVE-2026-20253, is rated 9.8 on the CVSS scoring system. "In Splunk Enterprise versions below 10.2.4 and 10.0.7, an unauthenticated user could create or truncate arbitrary
Watchtower Labs · Jun 12, 2026
Three posts? In three days? Are we insane?We're home alone, there's no one to stop us, and we're up past bedtime. So, we need to talk about Splunk. On June 10th, Splunk published this CVE-2026-20253 advisory:It has everything that we
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-07-18 10:54:12 UTC · 0 stars
pruva · Created 2026-07-07 21:08:36 UTC
Severity: CRITICAL | CVE: CVE-2026-20253 | Package: splunk/splunk
github · Created 2026-06-26 18:13:31 UTC · 0 stars
github · Created 2026-06-12 10:04:32 UTC · 2 stars
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
00:00 UTC 23 days ago00:00 UTC · 23 days ago
KEV confirmed by The Shadowserver
Exploitation attested by an external source
-
13:49 UTC about 1 month ago13:49 UTC · about 1 month ago
Virtual patch available
Compensating WAF rule available to block exploitation
-
18:20 UTC about 1 month ago18:20 UTC · about 1 month ago
KEV confirmed by All CISA Advisories
Exploitation attested by an external source
-
18:20 UTC about 1 month ago18:20 UTC · about 1 month ago
KEV confirmed by Daily CyberSecurity
Exploitation attested by an external source
-
17:41 UTC about 1 month ago17:41 UTC · about 1 month ago
KEV confirmed by CVE
Exploitation attested by an external source
-
00:00 UTC about 1 month ago00:00 UTC · about 1 month ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
05:15 UTC about 2 months ago05:15 UTC · about 2 months ago
Observed by KEVIntel sensors
Evidence-backed exploitation signal
-
05:15 UTC about 2 months ago05:15 UTC · about 2 months ago
Indicators of compromise added (59)
Indicators of compromise recorded
-
04:30 UTC about 2 months ago04:30 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
10:04 UTC about 2 months ago10:04 UTC · about 2 months ago
Public PoC available
Public proof-of-concept code published
-
17:16 UTC about 2 months ago17:16 UTC · about 2 months ago
CVE published
Vulnerability disclosed publicly
-
11:59 UTC 10 months ago11:59 UTC · 10 months ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2026-20253
{
"cve_id": "CVE-2026-20253",
"title": "Unauthenticated Arbitrary File Creation and Truncation in a PostgreSQL Sideca...",
"affected_vendor": "Splunk",
"affected_product": "Splunk Enterprise",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 9.8,
"epss_score": 0.96225,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": true
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}