What is CVE-2026-64609?

CVE-2026-64609 is a critical-severity vulnerability in Apache Fory, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-07-21.

How severe is CVE-2026-64609?

Critical severity. CVSS v3 base score is 9.1 out of 10.

Out-of-bounds Read in Apache Fory

CVE-2026-64609

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.

Vulnerability class: Buffer Overflow

Published 2026-07-21 · last modified 2026-07-27.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.008 (55.0th percentile), scored 2026-10-19.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 55th percentile — 55.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Apache Fory
Apache Software Foundation Fory — versions 0.11.0, 0.5.0

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

References

lists.apache.org/thread/rdv22ks3b0cxh0r52w3ghxgkxqso3f1b (vendor-advisory, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Third Party Advisory)

Frequently asked questions

What is CVE-2026-64609?: CVE-2026-64609 is a critical-severity vulnerability in Apache Fory, classified under Out-of-bounds Read. CVSS score: 9.1/10. Published 2026-07-21.
How severe is CVE-2026-64609?: Critical severity. CVSS v3 base score is 9.1 out of 10.