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9.8

CVE-2026-53151: Linux kernel: rxrpc SACK table parsing issue fixed

CVE-2026-53151 CVE-2026-53151
Summary

The Linux kernel has fixed a potential security issue in its rxrpc module that could be exploited by a maliciously crafted UDP packet. This issue has been resolved, and no action is required from users. However, it's essential to keep your Linux kernel up to date to ensure you have the latest security patches.

What to do

No fix is available yet. Check with your software vendor for updates.

Affected software
VendorProductAffected versions
linux linux < 5d1ae4e17a3ecd8561cdb4f4f70152f41039c4e1
6.2
linux linux_kernel >= 6.2, < 6.6.144
>= 6.7, < 6.12.95
>= 6.13, < 6.18.36
>= 6.19, < 7.0.13
7.1
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Original title
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix the ACK parser to extract the SACK table for parsing Fix modification of the received skbuff in rxrpc_input_soft_ack...
Original description
In the Linux kernel, the following vulnerability has been resolved:

rxrpc: Fix the ACK parser to extract the SACK table for parsing

Fix modification of the received skbuff in rxrpc_input_soft_acks() and a
potential incorrect access of the buffer in a fragmented UDP packet (the
packet would probably have to be deliberately pre-generated as fragmented)
when AF_RXRPC tries to extract the contents of the SACK table by copying
out the contents of the SACK table into a buffer before attempting to parse

AF_RXRPC assumes that it can just call skb_condense() and then validly
access the SACK table from skb->data and that it will be a flat buffer -
but skb_condense() can silently fail to do anything under some
circumstances.

Note that whilst rxrpc_input_soft_acks() should be able to parse extended
ACKs, the rest of AF_RXRPC doesn't currently support that.

Further, there's then no need to call skb_condense() in rxrpc_input_ack(),
so don't.
Published: 25 Jun 2026 · Updated: 23 Jul 2026 · First seen: 25 Jun 2026