Splunk AI Toolkit: Deserialization of Untrusted Data
CVE-2026-76395 is a high-severity deserialization of untrusted data vulnerability in Splunk AI Toolkit from Splunk, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists version 6.0.0 as the first without the flaw, so updating Splunk AI Toolkit to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.65% chance of exploitation within 30 days, higher than 52% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Splunk AI Toolkit to 6.0.0 or a later version.
- Update Ai Toolkit to 6.0.0 or a later version.
- Read the advisory on advisory.splunk.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Splunk | Splunk AI Toolkit | 5.7 up to, but not including, 6.0.0 | 6.0.0 |
| Splunk | Ai Toolkit | 5.7.0 up to, but not including, 6.0.0 | 6.0.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
In Splunk AI Toolkit versions below 6.0.0, a user who holds the "power" Splunk role could execute arbitrary code on the Splunk server by loading a model file containing crafted sparse matrix data. The deserialization of untrusted data is possible because a model codec in Splunk AI Toolkit deserializes sparse matrix data without guarding against embedded pickle content. For more information see Troubleshoot the Splunk Machine Learning Toolkit (https://help.splunk.com/en/splunk-cloud-platform/apply-machine-learning/machine-learning-toolkit-user-guide/5.5.0/troubleshooting-mltk/troubleshoot-the-splunk-machine-learning-toolkit) in the Splunk documentation.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Splunk AI Toolkit
- 8.1 High severity
- 8.1 High severity
- 7.5 High severity
- 8.3 High severity
- 8.3 High severity
- 9.1 Critical severity
Recent Deserialization of Untrusted Data vulnerabilities
- 9.8 Critical severity
- 9.1 Critical severity
- 8.4 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
Spotted an error? Tell us.