Apache Fory: Out-of-bounds Read
CVE-2026-64609 is a critical-severity out-of-bounds read vulnerability in Apache Fory from Apache, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 1.4.0, 0.11.0 as the first without the flaw, so updating Apache Fory to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.78% chance of exploitation within 30 days, higher than 56% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Apache Fory to 1.4.0 or 0.11.0, whichever matches your release line, or a later version.
- Update Fory to 1.4.0 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 | 0.11.0 up to, but not including, 1.4.0; 0.5.0 up to, but not including, 0.11.0 | 1.4.0, 0.11.0 |
| Apache | Fory | 0.5.0 up to, but not including, 1.4.0 | 1.4.0 |
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
- HighAll data handled by the component can be read.
- 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:H/I:N/A:H. Scored by CISA (ADP).
Official description
Out-of-bounds read via sun.misc.Unsafe in Apache Fory. When out-of-band zero-copy deserialization is used, readAlignedVarUint() can read beyond the bounds of the underlying buffer. Out-of-band zero-copy deserialization is an opt-in feature; applications that do not use it are not affected. This issue affects Apache Fory (formerly Apache Fury): from 0.5.0 before 1.4.0. Versions before 0.11.0 were published under the Maven coordinates org.apache.fury:fury-core. Users are recommended to upgrade to version 1.4.0, which fixes the issue.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
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
Third-party and government advisories
- openwall.com/lists/oss-security/2026/07/21/6Third Party Advisory
Other vulnerabilities in Apache Fory
- 9.1 Critical severity
- 7.5 High severity
- 9.8 Critical severity
- 7.3 High severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Out-of-bounds Read vulnerabilities
- 9.6 Critical severity
- 7.6 High severity
- 9.8 Critical severity
- 7.8 High severity
- 9.1 Critical severity
- 9.1 Critical severity
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