🛡️ CVE-2026-43284 — kernel
Description
xfrm: esp: avoid in-place decrypt on shared skb frags
In the Linux kernel, the following vulnerability has been resolved:
xfrm: esp: avoid in-place decrypt on shared skb frags
MSG_SPLICE_PAGES can attach pages from a pipe directly to an skb. TCP
marks such skbs with SKBFL_SHARED_FRAG after skb_splice_from_iter(),
so later paths that may modify packet data can first make a private
copy. The IPv4/IPv6 datagram append paths did not set this flag when
splicing pages into UDP skbs.
That leaves an ESP-in-UDP packet made from shared pipe pages looking
like an ordinary uncloned nonlinear skb. ESP input then takes the no-COW
fast path for uncloned skbs without a frag_list and decrypts in place
over data that is not owned privately by the skb.
Mark IPv4/IPv6 datagram splice frags with SKBFL_SHARED_FRAG, matching
TCP. Also make ESP input fall back to skb_cow_data() when the flag is
present, so ESP does not decrypt externally backed frags in place.
Private nonlinear skb frags still use the existing fast path.
This intentionally does not change ESP output. In esp_output_head(),
the path that appends the ESP trailer to existing skb tailroom without
calling skb_cow_data() is not reachable for nonlinear skbs:
skb_tailroom() returns zero when skb->data_len is nonzero, while ESP
tailen is positive. Thus ESP output will either use the separate
destination-frag path or fall back to skb_cow_data().
How this vulnerability can be exploited
This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- Attack vector: Local — a local account, shell or session on the host is needed.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: Low — an ordinary user account is enough.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Changed — a successful attack reaches components beyond the vulnerable one.
- Confidentiality impact: High — total loss, or loss the attacker controls.
- Integrity impact: High — total loss, or loss the attacker controls.
- Availability impact: High — total loss, or loss the attacker controls.
Affected software
CVE-2026-43284 is recorded against 2 packages.
- kernel (from 6.19.0 up to 7.0.5)
- linux-kernel (from 7.0 up to 7.0.5)
Timeline and source
Published on 8 May 2026 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.
References
www.openwall.com (Web)
www.openwall.com (Web)
www.openwall.com (Web)
www.openwall.com (Web)
cert-portal.siemens.com (Web)
cert-portal.siemens.com (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
security.access.redhat.com (Web)
www.vicarius.io (Web)
www.vicarius.io (Web)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
access.redhat.com (Advisory)
Other advisories for this package
kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:
- ALSA-2026:51035 (published 6 Aug 2026)
- ALSA-2026:50978 (published 6 Aug 2026)
- ALSA-2026:49871 (published 4 Aug 2026)
- ALSA-2026:49870 (published 4 Aug 2026)
- ALSA-2026:49857 (published 4 Aug 2026)
- ALSA-2026:49214 (published 31 Jul 2026)
- ALSA-2026:49212 (published 31 Jul 2026)
- ALSA-2026:49211 (published 31 Jul 2026)
CVE-2026-43284 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| kernel | 6.19.0 | 7.0.5 |
| linux-kernel | 7.0 | 7.0.5 |
References
Similar Threats
- Unknown ALBA-2026:39332
- Unknown ALSA-2023:1703
- Unknown ALSA-2023:1566
- Unknown ALSA-2023:1470
- Unknown ALSA-2023:0951
Site Security Check
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