CVE-2026-43284
HighExploitedPublic exploitkernel: "Dirty Frag" ESP XFRM variant is a new universal Local Privilege Escalation (LPE) vulnerability in the Linux kernel
Published May 12, 2026 · Updated Oct 15, 2026 · Also known as DEBIAN-CVE-2026-43284, ROOT-OS-DEBIAN-11-CVE-2026-43284, ROOT-OS-DEBIAN-12-CVE-2026-43284, UBUNTU-CVE-2026-43284, USN-8388-1, USN-8388-2, USN-8389-1, USN-8390-1, USN-8390-2, USN-8461-1, USN-8462-1
Key Facts
Patch immediately- CVE-2026-43284 is a high-severity vulnerability (CVSS 7.8 v3.1) affecting linux-aws-6.12 (chainguard), linux-aws-6.18 (chainguard), linux-azure-6.12 (chainguard) and 22 more products.
- It is exploited in the wild, listed in Industry KEV feed since May 8, 2026. Public exploit code is available.
- EPSS estimates a 94% probability of exploitation in the next 30 days.
- Fixed versions are available, including bpftool 1:6.1.170-210.320.amzn2023, bpftool 4.18.0-553.124.1.el8_10, bpftool 5.10.255-1.ph4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.8
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
94%
Higher than 99.8% of all scored CVEs
Exploited in the wild
Yes
1 catalog listing
Public exploit code
Available
Proof-of-concept or weaponized module
Get the full CVE-2026-43284 brief as a PDF
Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.
Description
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().
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | May 8, 2026 | n/a | Not reported |
Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.
Affected Products
5,706 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| linux-aws-6.12chainguard | See advisory | 6.12.85-r2 |
| linux-aws-6.18chainguard | See advisory | 6.18.31-r0 |
| linux-azure-6.12chainguard | See advisory | 6.12.85-r2 |
| linux-azure-6.18chainguard | See advisory | 6.18.24-r1 |
| linux-gcp-6.12chainguard | See advisory | 6.12.85-r2 |
Patched Releases
bpftool
1:6.1.170-210.320.amzn2023, 4.18.0-553.124.1.el8_10, 5.10.255-1.ph4, 5.15.0-318.199.3.6.el8uek, 5.15.0-318.199.3.6.el9uek, 5.15.0-319.201.4.6.el8uek, 5.15.0-319.201.4.6.el9uek, 5.15.0-320.202.8.2.el8uek, 5.15.0-320.202.8.2.el9uek, 5.15.0-321.202.5.el8uek, 5.15.0-321.202.5.el9uek, 6.1.172-1.ph5, 6.1.177-1.ph5, 7.7.0+6.17.0-35.35, 7.7.0+7.0.0-22.22
bpftool6.12
1:6.12.83-113.160.amzn2023
bpftool6.18
1:6.18.25-55.108.amzn2023
cluster-md-kmp-64kb
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
cluster-md-kmp-azure
6.12.0-160000.30.1, 6.12.0-160000.36.1
cluster-md-kmp-default
4.12.14-122.307.1, 4.12.14-122.320.1, 5.14.21-150400.24.209.1, 5.14.21-150500.55.163.1, 6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1, 6.4.0-150600.23.115.1, 6.4.0-150700.53.45.1, 6.4.0-150700.53.60.1, 6.4.0-150700.53.66.1
cluster-md-kmp-rt
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150700.7.44.1, 6.4.0-150700.7.51.1, 6.4.0-150700.7.59.2, 6.4.0-150700.7.62.1
dlm-kmp-64kb
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dlm-kmp-azure
6.12.0-160000.30.1, 6.12.0-160000.36.1
dlm-kmp-default
4.12.14-122.307.1, 4.12.14-122.320.1, 5.14.21-150400.24.209.1, 5.14.21-150500.55.163.1, 6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1, 6.4.0-150600.23.115.1, 6.4.0-150700.53.45.1, 6.4.0-150700.53.60.1, 6.4.0-150700.53.66.1
dlm-kmp-rt
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150700.7.44.1, 6.4.0-150700.7.51.1, 6.4.0-150700.7.59.2, 6.4.0-150700.7.62.1
dtb-allwinner
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-altera
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-amazon
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-amd
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-amlogic
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-apm
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-apple
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-arm
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-broadcom
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-cavium
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-exynos
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-freescale
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-hisilicon
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
dtb-lg
6.12.0-160000.30.1, 6.12.0-160000.36.1, 6.4.0-150600.23.103.1
Timeline
Added to Industry KEV feed
May 8, 2026
Publicly disclosed
May 12, 2026
Last updated
Oct 15, 2026
Weakness Type
- CWE-123 Write-what-where Condition
References
- advisoryRHSA-2026:16061
- advisoryRHSA-2026:16062
- advisoryRHSA-2026:16100
- advisoryRHSA-2026:16155
- advisoryRHSA-2026:16157
FAQ
Common Questions.
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.
Affected: linux-aws-6.12 (chainguard); linux-aws-6.18 (chainguard); linux-azure-6.12 (chainguard), among others. The full list is in the CVE brief.
It is exploited in the wild, listed in Industry KEV feed since May 8, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
Public exploit code is available.
Fixed versions are available, including bpftool 1:6.1.170-210.320.amzn2023, bpftool 4.18.0-553.124.1.el8_10, bpftool 5.10.255-1.ph4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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