data built 2026-10-19T13:16:53Z

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CVE-2026-98383

bpf: Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL

EPSS 0.2%

Published 2026-10-09 (10 days ago) by the Linux kernel CNA. Subsystem net/core. Debian urgency: not yet assigned.

What to do, per Debian release

Debian's own status for CVE-2026-98383 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source

ReleaseStatus VersionWhat this means
Debian 12bookwormfixedDLA-4841-1 · 2026-10-17 · text6.1.190-1Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts.
Debian 13trixiefixedDSA-6568-1 · 2026-10-16 · text6.12.113-1Update the kernel and reboot. DSA-6568-1 shipped the fix on 2026-10-16, in 6.12.113-1. A running kernel keeps the old code until the machine restarts.
Debian 14forkyfixed7.2.9-1Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesidfixed7.2.9-1Update the kernel and reboot. Fixed in 7.2.9-1. A running kernel keeps the old code until the machine restarts.

The vulnerability

What the bug is

An LWT_SEG6LOCAL program can invalidate its cached SRH with bpf_lwt_seg6_adjust_srh() and then call bpf_skb_pull_data(). The latter may reallocate skb->head, leaving the per-CPU SRH pointer dangling. Post-program SRH validation then writes through that pointer. Disallow bpf_skb_pull_data() for LWT_SEG6LOCAL programs so the verifier rejects this unsafe helper combination. Other LWT program types continue to expose the helper through lwt_out_func_proto().

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

net/core/filter.c

What this is
BPF [GENERAL] (Safe Dynamic Programs and Tools)MAINTAINERS section matched on net/core/filter.c · bpf@vger.kernel.org · Supported
Show whether Debian builds this, per release

Debian builds this code. Every release below compiles the affected file into the kernels it ships.

  • bookworm, trixie, forky, sidy
y
built into the kernel image on every flavour - only a patch removes it

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS Debian linux-config packages

Signals

Published
2026-10-09 (10 days ago)source
CVSS
no vector published, unrated
Attack vector
not published
EPSS
0.16%, higher than 5.3% of all CVEssource
CISA KEV
not listedthe KEV catalogue
Debian urgency
not yet assignedsource
Subsystem
net/core

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

IntroducedFixed inCommit
4.185.10.2710f38472a2aa8
4.185.15.222cae8674489f2
4.186.1.1899f9e57b5a3a0
4.186.6.158df0072be6fc3
4.186.12.112b9bb0e735460
4.186.18.5537b18688cd18
4.187.2.9fca71ead7a20
4.187.3e4a62833adff

Debian advisories

AdvisoryDateShipped toDebian
DLA-4841-12026-10-17bookworm 6.1.190-1tracker
DSA-6568-12026-10-16trixie 6.12.113-1tracker

Why the CNA scored it this way

The kernel CNA published no CVSS vector and no reasoning for CVE-2026-98383, which is why it is shown as unrated rather than given an invented score. 6,405 of the 20,413 CVEs here carry reasoning; this is not one of them.