CVE-2026-53362: Linux Kernel Unspecified Vulnerability

Q: How do I fix CVE-2026-53362?

linux kernel: upgrade to 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3; simatic s7-1500 tm mfp firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2026-53362 being exploited?

Yes. CVE-2026-53362 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2026-53362 affect?

CVE-2026-53362 affects linux kernel, simatic s7-1500 tm mfp firmware. Severity is high (CVSS 7.8). In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen

Q: How urgent is CVE-2026-53362?

Priority 71/100. High severity; Exploited in the wild (CISA KEV); On your watchlist

Patch now

HIGH 7.8EXPLOITEDWATCHLISTUPGRADEMITIGATE

CVE-2026-53362 is a high-severity flaw (CVSS 7.8) affecting linux kernel, simatic s7-1500 tm mfp firmware, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap (datalen = length + fraggap). When fraggap is non-zero, this is not t

Why this priority

High severity
Exploited in the wild (CISA KEV)
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.8 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.7% (top 47%)
CISA exploited list	Yes, fix due 2026-08-30
Weakness	CWE-787, CWE-122
Published	2026-07-04
Last modified	2026-10-15

Publisher (CNA): kernel.org · Vendor: linux · siemens

Am I affected?

Timeline

2026-07-04 12:17 UTCPublished CVE record published
2026-08-27Exploited Added to the CISA Known Exploited Vulnerabilities list
2026-08-30Deadline CISA due date for US federal agencies to patch
2026-10-15 13:46 UTCUpdated Record last modified

linux linux kernel UPGRADE

Affected: >= 6.0 and < 6.1.177 · >= 6.2 and < 6.6.144 · >= 6.7 and < 6.12.95 · >= 6.13 and < 6.18.38 · >= 6.19 and < 7.1.3

Fixed in: 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

siemens simatic s7-1500 tm mfp firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · python-streamlink · FIXED · 8.6.2-1.fc46 · FEDORA-2026-a56fcfdc08 · source

sudo dnf upgrade --advisory=FEDORA-2026-a56fcfdc08

Fedora ELN · valgrind · FIXED · 3.28.0-1.eln159 · FEDORA-2026-c593ef1d15 · source

sudo dnf upgrade --advisory=FEDORA-2026-c593ef1d15

Ubuntu 20.04 · linux · NOT AFFECTED

Ubuntu 22.04 · linux · NOT AFFECTED

Ubuntu 24.04 · linux · FIXED · 6.8.0-147.147

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.8.0-147.147" && echo PATCHED || echo STILL-VULNERABLE

Ubuntu 20.04 · linux-hwe-5.15 · NOT AFFECTED

Ubuntu 22.04 · linux-hwe-6.8 · NO FIX YET

Debian 12 · linux · FIXED · 6.1.177-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.1.177-1" && echo PATCHED || echo STILL-VULNERABLE

Debian 13 · linux · FIXED · 6.12.95-1

sudo apt update && sudo apt install --only-upgrade linux dpkg --compare-versions "$(dpkg-query -W -f='${Version}' linux)" ge "6.12.95-1" && echo PATCHED || echo STILL-VULNERABLE

RHEL 10 · kernel · FIXED · kernel-6.12.0-211.30.1.el10_2

sudo dnf upgrade --advisory=RHSA-2026:34911 rpm -q kernel

RHEL 10.0 Extended Update Support · kernel · FIXED · kernel-6.12.0-55.86.1.el10_0

sudo dnf upgrade --advisory=RHSA-2026:35840 rpm -q kernel

RHEL 6 · kernel · NOT AFFECTED

RHEL 7 · kernel · NOT AFFECTED

RHEL 7 · kernel-rt · NOT AFFECTED

Amazon Linux 2023 · see advisory · FIXED · ALAS2023-2026-1938 · source

sudo dnf update --advisory=ALAS2023-2026-1938

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: suominen/ipv6_frag_escape (0 stars)
Write-up: cert-portal.siemens.com/productcert/html/ssa-784472.html

Verify at the official source NVD · CVE Program · CISA KEV catalog · 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-2026-53362?

linux kernel: upgrade to 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3; simatic s7-1500 tm mfp firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2026-53362 being exploited?

Yes. CVE-2026-53362 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2026-53362 affect?

CVE-2026-53362 affects linux kernel, simatic s7-1500 tm mfp firmware. Severity is high (CVSS 7.8). In the Linux kernel, the following vulnerability has been resolved: ipv6: account for fraggap on the paged allocation path In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen

How urgent is CVE-2026-53362?

Priority 71/100. High severity; Exploited in the wild (CISA KEV); On your watchlist

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References

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