How to Fix CVE-2026-31501: net: ti: icssg-prueth: fix use-after-free of CPPI descriptor in Linux

By Sai Kiran Pandrala

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Last verified: 2026-05-25

CVE-2026-31501 is a net: ti: icssg-prueth: fix use-after-free of cppi descriptor in Linux Linux. Fix it by upgrading to 6.19.11, 7.0.

What is CVE-2026-31501?

CVE-2026-31501 is a net: ti: icssg-prueth: fix use-after-free of cppi descriptor flaw in Linux Linux. It carries a CVSS base score of 9.8 (critical). 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: ti: icssg-prueth: fix use-after-free of CPPI descriptor in RX path

cppi5_hdesc_get_psdata() returns a pointer into the CPPI descriptor.

In both emac_rx_packet() and emac_rx_packet_zc(), the descriptor is

freed via k3_cppi_desc_pool_free() before the psdata pointer is used

by emac_rx_timestamp(), which dereferences psdata[0] and psdata[1].

This constitutes a use-after-free on every received packet that goes

through the timestamp path.

Defer the descriptor free until after all accesses through the psdata

pointer are complete. For emac_rx_packet(), move the free into the

requeue label so both early-exit and success paths free the descriptor

after all accesses are done. For emac_rx_packet_zc(), move the free to

the end of the loop body after emac_dispatch_skb_zc() (which calls

emac_rx_timestamp()) has returned.

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-2026-31501

Apply the vendor patch. Target the build named in the Fixed in row above (6.19.11, 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 6.19.11, 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-2026-31501 being exploited in the wild?

As of 2026-05-25, CVE-2026-31501 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-2026-31501?

The CVSS base score is 9.8 (Critical).

What version fixes this?

Upgrade to 6.19.11, 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

• Official vendor advisory: https://git.kernel.org/stable/c/d5827316debcb677679bb014885d7be92c410e11
• NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2026-31501
• CISA KEV catalog: https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• Additional reference: https://git.kernel.org/stable/c/eb8c426c9803beb171f89d15fea17505eb517714

*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.*