CVE-2026-53366

In the Linux kernel, the following vulnerability has been resolved: ipv4: account for fraggap on the paged allocation path In __ip_append_data(), when the paged-allocation branch is taken, alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap, but the fraggap bytes carried over from the previous skb are copied into the new skb's linear area at offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount. 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.

CVSS 3.1

7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 6% of CVEs (scores of 2026-10-25)

CWE

CWE-131

Published

2026-07-16

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• linux:linux_kernel

References

• https://git.kernel.org/stable/c/5c6375bced6147ec2e460ee3b653f4860d5ecdc2
• https://git.kernel.org/stable/c/77798d7be6ef71e72fb6fc8a2901bf74ebc9706f
• https://git.kernel.org/stable/c/a9c24eda24bd15f432e37824e6fc440977cb241c
• https://git.kernel.org/stable/c/c04d9ece23deb9e26c19f9ca215e98b3295aa1bb
• https://git.kernel.org/stable/c/ce494707a9c07f27c219ca67f3e138061f53d9b3

Check your stackJSON