⚠ Reference material — not professional advice. Test in staging, back up first, verify against your specific version. Use your own judgment for your environment.
● High · CVSS 7.5

How to Fix CVE-2026-43031: net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets in Linux

By Sai Kiran Pandrala

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

Last verified: 2026-05-25

CVE-2026-43031 is a net: xilinx: axienet: fix bql accounting for multi-bd tx packets in Linux Linux. Fix it by upgrading to 6.18.22, 6.19.12, 7.0.

⚡ At a glance
SeverityCVSS 7.5 - High
Actively exploited?Not currently in the CISA KEV catalog
AffectedLinux c900e49d58eb32b192b6d200ace4ae3ab89779d4 up to (excluding) 2a0323a913109b52bfc9f5ea7b92a1b249e07d3e; Linux c900e49d58eb32b192b6d200ace4ae3ab89779d4 up to (excluding) 3c3a6b9020c01fde7b22e8550105de0b59904f61; Linux c900e49d58eb32b192b6d200ace4ae3ab89779d4 up to (excluding) d1978d03e86785872871bff9c2623174b10740de; Linux 6.15
Fixed in6.18.22, 6.19.12, 7.0
Type (CWE)Not verified

What is CVE-2026-43031?

CVE-2026-43031 is a net: xilinx: axienet: fix bql accounting for multi-bd tx packets flaw in Linux Linux. It carries a CVSS base score of 7.5 (high). It is not currently listed in the CISA Known Exploited Vulnerabilities catalog.

From the source record: In the Linux kernel, the following vulnerability has been resolved:

net: xilinx: axienet: Fix BQL accounting for multi-BD TX packets

When a TX packet spans multiple buffer descriptors (scatter-gather),

axienet_free_tx_chain sums the per-BD actual length from descriptor

status into a caller-provided accumulator. That sum is reset on each

NAPI poll. If the BDs for a single packet complete across different

polls, the earlier bytes are lost and never credited to BQL. This

causes BQL to think bytes are permanently in-flight, eventually

stalling the TX queue.

The SKB pointer is stored only on the last BD of a packet. When that

BD completes, use skb->len for the byte count instead of summing

per-BD status lengths. This matches netdev_sent_queue(), which debits

skb->len, and naturally survives across polls because no partial

packet contributes to the accumulator.

Why it matters in practice: The blast radius depends on how the affected service is exposed. An internet-facing instance with no compensating controls is the highest-risk configuration.

Am I affected?

You are affected if your installation of Linux matches a version listed in the Affected row above.


# Debian/Ubuntu
dpkg -s linux | grep Version
# RHEL/Rocky
rpm -q linux

How to fix CVE-2026-43031

Apply the vendor patch. Target the build named in the Fixed in row above (6.18.22, 6.19.12, 7.0). The runnable command set below covers the most common deployment patterns for Linux.

Ubuntu / Debian


sudo apt-get update
sudo apt-get install --only-upgrade linux
dpkg -s linux | grep Version

RHEL / CentOS / Rocky


sudo dnf upgrade linux -y
rpm -q linux

After applying the patch

  1. Restart the service or device so the patched binary loads.
  2. Confirm the running version matches the Fixed in row using the verification command below.
  3. Rotate credentials and API keys that the affected service could access if the asset was exposed during the disclosure window.

If you can't patch immediately

Until the patch lands, narrow the attack surface with these runnable controls.

Restrict network exposure

Block public access to the affected service at the perimeter. Allow only trusted source IPs.


# Linux iptables: only allow trusted admin subnet
sudo iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 443 -j DROP
sudo iptables-save | sudo tee /etc/iptables/rules.v4


# Windows firewall: only allow trusted admin subnet on management port
New-NetFirewallRule -DisplayName "Restrict-Mgmt-Allow" -Direction Inbound -Action Allow `
  -RemoteAddress 10.10.10.0/24 -Protocol TCP -LocalPort 443
New-NetFirewallRule -DisplayName "Restrict-Mgmt-Deny"  -Direction Inbound -Action Block `
  -Protocol TCP -LocalPort 443

Mitigations are temporary. Apply the vendor patch as soon as a maintenance window opens.

How to verify the fix worked

Confirm the patched build is the one actually running.


# Debian/Ubuntu
dpkg -s linux | grep Version
# RHEL/Rocky
rpm -q linux

Expected: a version at or above 6.18.22, 6.19.12, 7.0.

Also worth doing: pull recent log windows for indicators of compromise listed in the vendor advisory, and re-run an authenticated vulnerability scan with up-to-date signatures.

Frequently asked questions

Is CVE-2026-43031 being exploited in the wild?

As of 2026-05-25, CVE-2026-43031 is not listed in the CISA Known Exploited Vulnerabilities catalog. Watch the catalog and patch on a normal cadence; KEV status can change as exploitation evidence emerges.

What is the CVSS score for CVE-2026-43031?

The CVSS base score is 7.5 (High).

What version fixes this?

Upgrade to 6.18.22, 6.19.12, 7.0.

Will a WAF or IDS rule alone close this?

No. Network filters cut down opportunistic scans but they do not remove the flaw. The vendor patch is the only durable fix.

References

*Assembled from the official vendor advisory, the NVD record, and the CISA KEV listing on 2026-05-25. Always confirm against the vendor advisory before applying changes in production.*