CVE-2026-53362

What it is

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 the first skb and transhdrlen is zero. The fraggap bytes carried over from the previous skb are copied just past the fragment headers in the new skb's linear area. The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount, and the copy writes past skb->end into the trailing skb_shared_info. An unprivileged user can trigger this via a UDPv6 socket using MSG_MORE together with MSG_SPLICE_PAGES. The bad accounting was introduced by commit 773ba4fe9104 ("ipv6: avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix __ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative copy value caused -EINVAL to be returned. That later commit allowed MSG_SPLICE_PAGES to proceed in this case, making the corruption triggerable. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES case, remove the MSG_SPLICE_PAGES exception from the negative copy check.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

In the wild

CISA lists this as exploited in real attacks. Treat as urgent.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-06-09 07:44 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-07-04 12:17 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-08-27 Exploited in the wildAdded to CISA's Known Exploited Vulnerabilities list
4. 2026-08-30 Remediation deadlineCISA's due date for federal agencies to fix it
5. 2026-10-15 13:46 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: yes, CISA lists it. This puts it above everything that is not.
• Exploit odds: 0.7% in the next 30 days (EPSS).
• Severity: 7.8 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-07-04 12:17 UTC

Last modified

2026-10-15 13:46 UTC

Added to CISA KEV

2026-08-27

Exploit probability

0.7% · EPSS, next 30 days

Weakness

CWE-787 · Out-of-bounds write

Record status

Analyzed

Affected

• Linux Kernel < 6.1.177
• Linux Kernel < 6.6.144
• Linux Kernel < 6.12.95
• Linux Kernel < 6.18.38
• Linux Kernel < 7.1.3
• Siemens Simatic s7-1500 Tm Mfp Firmware

Attack profile CVSS 3.1 · 7.8

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-53362.md and follow it. Check whether this project is affected by CVE-2026-53362. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

Copy as ticket · More options · Status badge