CVE-2026-48207: Deserialization of untrusted data in Apache Fory PyFory

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CRITICAL 9.8REMOTEWATCHLISTUPGRADE

CVE-2026-48207 is a critical-severity flaw (CVSS 9.8) affecting fory. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Deserialization of untrusted data in Apache Fory PyFory. PyFory's ReduceSerializer could bypass documented DeserializationPolicy validation hooks during reduce-state restoration and global-name resolution. An application is vulnerable if it deserializes attacker-controlled data using PyFory Python-native mode with strict mode disabled and relies on DeserializationPolicy to restrict unsafe classes, functions, or module attributes. This issue affe

Why this priority

Critical severity
CISA SSVC: automatable with total technical impact
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.6% (top 53%)
CISA exploited list	No
Weakness	CWE-502
Published	2026-05-21
Last modified	2026-07-23

Publisher (CNA): Apache Software Foundation · Vendor: apache

Last updated 2026-07-23 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-21 17:16 UTCPublished CVE record published
2026-07-23 16:10 UTCUpdated Record last modified

apache fory UPGRADE

Affected: >= 0.13.0 and < 1.0.0

Fixed in: 1.0.0

Safe to downgrade to: a release before 0.13.0

1. Check installed version

apt-cache policy fory || rpm -q fory || fory --version

2. UPGRADE to 1.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade fory

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade fory

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 0.13.0 (Debian / Ubuntu)

apt-cache madison fory sudo apt install fory=<VERSION_BEFORE_0.13.0> sudo apt-mark hold fory

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list fory sudo dnf downgrade fory-<VERSION_BEFORE_0.13.0> sudo dnf versionlock add fory

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Python (pip) · pyfory · FIXED · 1.0.0 · vulnerable: >= 0.13.0, < 1.0.0 · source

pip install --upgrade "pyfory>=1.0.0" pip show pyfory

Fedora 46 · proftpd · FIXED · 1.3.9e-1.fc46 · FEDORA-2026-fc0d87d66e · source

sudo dnf upgrade --advisory=FEDORA-2026-fc0d87d66e

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-48207?

fory: upgrade to 1.0.0. Exact commands for each OS are on this page.

Is CVE-2026-48207 being exploited?

CVE-2026-48207 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-48207 affect?

CVE-2026-48207 affects fory. Severity is critical (CVSS 9.8). Deserialization of untrusted data in Apache Fory PyFory. PyFory's ReduceSerializer could bypass documented DeserializationPolicy validation hooks during reduce-state restoration and global-name resolution. An application is vulnerable if it

How urgent is CVE-2026-48207?

Priority 59/100. Critical severity; CISA SSVC: automatable with total technical impact; Remotely exploitable, no login, no user action; On your watchlist

Software pages

Python vulnerabilities

Related CVEs

CVE-2026-64608 CRITICAL 9.8 UPGRADE Heap type confusion and out-of-bounds read/write in the Apache Fory C++ implementation
CVE-2026-64606 CRITICAL 9.8 UPGRADE Deserialization of untrusted data vulnerability that may allow class-registration checks to be bypassed during
CVE-2026-64609 CRITICAL 9.1 UPGRADE Out-of-bounds read via sun.misc.Unsafe in Apache Fory
CVE-2026-60080 HIGH 7.3 UPGRADE Use After Free vulnerability in the Rust deserialization logic of Apache Fory
CVE-2026-71558 CRITICAL 9.8 UPGRADE Heap type confusion vulnerability in Apache Fory C++ deserialization. This issue affects Apache Fory C++ vers

References

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