Apache Fory: Deserialization of Untrusted Data
CVE-2026-71559 is a high-severity deserialization of untrusted data vulnerability in Apache Fory from Apache, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 1.5.0 as the first without the flaw, so updating Apache Fory to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.8% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Apache Fory to 1.5.0 or a later version.
- Update Fory to 1.5.0 or a later version.
- Read the advisory on lists.apache.org for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Apache | Apache Fory | 0.16.0 up to, but not including, 1.5.0 | 1.5.0 |
| Apache | Fory | 0.16.0 up to, but not including, 1.5.0 | 1.5.0 |
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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CISA (ADP).
Official description
Deserialization of Untrusted Data vulnerability in the Go implementation of Apache Fory allows an attacker to cause a denial of service by supplying crafted data containing malformed type metadata, which triggers an uncaught panic. This issue affects Apache Fory: from 0.16.0 before 1.5.0. Users of other language implementations are not affected. Users are recommended to upgrade to version 1.5.0, which fixes the issue.
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: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- openwall.com/lists/oss-security/2026/08/07/4Mailing List, Third Party Advisory
Other vulnerabilities in Apache Fory
- 9.1 Critical severity
- 9.8 Critical severity
- 7.3 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
Recent Deserialization of Untrusted Data vulnerabilities
- 8.0 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.0 Critical severity
- 7.6 High severity
- 8.8 High severity
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