● Not verified

How to Fix CVE-2026-25087: Use-After-Free in Apache Arrow

Q: Is CVE-2026-25087 being exploited in the wild?

Public exploitation has not been confirmed by CISA at the time of writing. Treat the patch as time-sensitive anyway; reports often lag actual abuse.

Q: Will a WAF or IDS rule fully mitigate CVE-2026-25087?

No. Network-layer filters can reduce noise and slow opportunistic scanners, but they will not stop a determined attacker. The vendor patch is the only durable fix.

Q: How long should I plan for the upgrade?

Typical vendor-documented upgrade windows for Apache Arrow run from a few minutes to under an hour depending on cluster size. Test in a staging environment first and follow the vendor's documented HA upgrade order.

Other vulnerabilities in the same area that are worth patching alongside this one:

How to Fix CVE-2026-32642: Access Control Bypass in Apache Artemis — Access Control Bypass in Apache Artemis
How to Fix CVE-2026-31910: SSRF Vulnerability in Apache OFBiz — SSRF Vulnerability in Apache OFBiz
How to Fix CVE-2026-31906: Cross-Site Scripting in Apache OFBiz , Cross-Site Scripting in Apache OFBiz
How to Fix CVE-2026-40023: Encoding or escaping of output in Apache Log4cxx , Encoding or escaping of output in Apache Log4cxx
How to Fix CVE-2026-41018: Insertion of Sensitive Information into Log File , Insertion of Sensitive Information into Log File

*By Sai Kiran Pandrala*

⚡ At a glance


Severity	Not verified - see advisory
Actively exploited?	Not currently listed in CISA KEV
Affected	15.0.0 <= 23.0.0
Fixed in	23.0.1
Type (CWE)	CWE-416: Use After Free

What is CVE-2026-25087?

CVE-2026-25087 is an use-after-free bug in Apache Arrow. A reference to freed memory is dereferenced later in the program, allowing an attacker who controls the reallocated content to hijack execution. Vendor description: Use After Free vulnerability in Apache Arrow C++. This issue affects Apache Arrow C++ from 15.0.0 through 23.0.0.

Why this CVE matters

Use-after-free vulnerabilities in a network or media-parsing path tend to draw immediate exploit development effort. The bug class is well understood, and public toolkits exist that adapt quickly to newly disclosed cases.

For deployments of Apache Arrow that have been exposed to the public internet during the disclosure window, the operating assumption should be that scanning has already happened. Even where exploitation has not been publicly observed, scanning for the vulnerable fingerprint is cheap and routine. Patching closes the door; log review and credential rotation close out the rest of the response.

Am I affected?

You are affected if your installation matches any of these version ranges:

Apache Arrow: 15.0.0 <= 23.0.0

Check your installed version against the list above. If you cannot determine the version, treat the system as affected and follow the upgrade path below.

Run the project-specific version command (for example httpd -v, tomcat version, or check pom.xml / package metadata) and compare against the advisory.

How to fix CVE-2026-25087

Read the vendor advisory in full: https://github.com/apache/arrow/pull/48925
Upgrade Apache Arrow to 23.0.1 or a later version listed in the vendor advisory.
Back up the configuration (and database, where applicable) before upgrading.
Apply the patch in a maintenance window. For HA pairs, upgrade the standby node first, fail over, then upgrade the former primary.
Restart the affected service so the patched binary loads, then verify the new version (see verification section).

Patched-version commands

Vendor advisory: https://github.com/apache/arrow/pull/48925

Affected: Apache Arrow: 15.0.0 <= 23.0.0

Patched in: 23.0.0


# Vendor advisory: https://github.com/apache/arrow/pull/48925

# Debian / Ubuntu.
sudo apt update
sudo apt install --only-upgrade apache2
sudo systemctl restart apache2

# RHEL / Rocky / AlmaLinux / Fedora (use httpd for Apache).
sudo dnf upgrade httpd
sudo systemctl restart httpd

# Verify the running version matches 23.0.0 from the advisory.
apache2 -v


# Vendor advisory: https://github.com/apache/arrow/pull/48925
# IIS-hosted equivalent on Windows.
Install-Module PSWindowsUpdate -Force -SkipPublisherCheck -Confirm:$false
Get-WindowsUpdate -AcceptAll -Install -AutoReboot
Restart-WebAppPool -Name "<AppPoolName>"

Verify the fix landed


# Vendor advisory: https://github.com/apache/arrow/pull/48925
# Post-patch verification (replace <service> with the real service unit).
journalctl -u <service> --since "10 minutes ago"
dmesg --since "10 minutes ago"

# Re-scan with your vulnerability scanner (Nessus, Qualys, Tenable, OpenVAS).
# It should no longer flag CVE-2026-25087 on the patched target.

If you cannot patch immediately

Block network reachability to the vulnerable service from untrusted networks and apply the patched build. Memory-corruption bugs cannot be reliably mitigated at the network layer; the patch is the fix.

How to verify the fix worked

After applying the patch, verify the running version in the product's admin UI or via the vendor-documented CLI command.
Confirm the patched build matches the version listed in the vendor advisory.
Run an authenticated vulnerability scan with a current signature set and confirm the scanner no longer flags CVE-2026-25087.
Review logs for the entire pre-patch window for indicators of compromise listed in the vendor or CISA advisory.
Confirm any network-layer mitigations that were applied as a stopgap have been reverted (or left in place intentionally) once the patch is verified.

If your installation was internet-reachable during the disclosure window, treat log review as part of the remediation rather than an optional follow-up. Look for repeated service restarts, crash logs from the affected daemon, and core files generated around the time of any anomalous traffic. A memory-corruption flaw used for exploitation often leaves a trail of failed attempts before the successful one.

Frequently asked questions

Is CVE-2026-25087 being exploited in the wild?