Core: Deserialization of Untrusted Data
CVE-2026-102101 is a high-severity deserialization of untrusted data vulnerability in Core from Kiteworks, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. The record lists version 9.5.0 as the first without the flaw, so updating Core to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.94% chance of exploitation within 30 days, higher than 61% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Core to 9.5.0 or a later version.
- Update Kiteworks to 9.5.0 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Kiteworks | Core | before 9.5.0 | 9.5.0 |
| Accellion | Kiteworks | before 9.5.0 | 9.5.0 |
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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:L/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA.
Official description
Kiteworks Core before version 9.5.0 is vulnerable to Deserialization of Untrusted Data. A deserialization weakness in Kiteworks Core could, under certain conditions, allow crafted data to be deserialized unsafely, potentially resulting in remote code execution on the appliance. Exploitation depends on an attacker first being able to influence the affected data, so this issue is not exploitable on its own.
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 Core
- 9.3 Critical severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 8.1 High severity
- 8.8 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 7.2 High severity
- 7.2 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.2 High severity
- 9.8 Critical severity
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