CVE-2026-46300linux Out-of-Bounds Write
kernel: "Fragnesia" is a variant of Dirty Frag vulnerability in the ESP/XFRM leading to Local Privilege Escalation (LPE) vulnerability in the Linux kernel
Published May 13, 2026 · Updated Oct 16, 2026 · Also known as DEBIAN-CVE-2026-46300, EUVD-2026-31535, GHSA-47jg-vqrv-5f8v, ROOT-OS-DEBIAN-11-CVE-2026-46300, ROOT-OS-DEBIAN-12-CVE-2026-46300, ROOT-OS-DEBIAN-13-CVE-2026-46300, UBUNTU-CVE-2026-46300, USN-8373-1
Key Facts
Patch immediately- CVE-2026-46300 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 Aug 3, 2026. A public exploit is reported by tracking sources, but no code link is listed yet.
- EPSS estimates a 2.4% probability of exploitation in the next 30 days.
- Fixed versions are available, including bpftool 1:6.1.170-213.321.amzn2023, bpftool 4.18.0-553.125.1.el8_10, bpftool 5.10.258-1.ph4.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
Scores
CVSS v3.1
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
2.4%
Exploit maturity
Weaponized
ATLAS score
51/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Aug 3, 2026
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
Weaponized
Public exploit code
2
Proof-of-concept links
In-the-wild evidence
3
Reports of active use
Advisories And Exploit References
Description
In the Linux kernel, the following vulnerability has been resolved:
net: skbuff: preserve shared-frag marker during coalescing
skb_try_coalesce() can attach paged frags from @from to @to. If @from has SKBFL_SHARED_FRAG set, the resulting @to skb can contain the same externally-owned or page-cache-backed frags, but the shared-frag marker is currently lost.
That breaks the invariant relied on by later in-place writers. In particular, ESP input checks skb_has_shared_frag() before deciding whether an uncloned nonlinear skb can skip skb_cow_data(). If TCP receive coalescing has moved shared frags into an unmarked skb, ESP can see skb_has_shared_frag() as false and decrypt in place over page-cache backed frags.
Propagate SKBFL_SHARED_FRAG when skb_try_coalesce() transfers paged frags. The tailroom copy path does not need the marker because it copies bytes into @to's linear data rather than transferring frag descriptors.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| Industry KEV feed | Aug 3, 2026 | n/a | Not reported |
Affected Products
4,544 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| linux-aws-6.12chainguard | See advisory | 6.12.92-r0 |
| linux-aws-6.18chainguard | See advisory | 6.18.34-r0 |
| linux-azure-6.12chainguard | See advisory | 6.12.92-r0 |
| linux-azure-6.18chainguard | See advisory | 6.18.34-r0 |
| linux-gcp-6.12chainguard | See advisory | 6.12.92-r0 |
Patched Releases
bpftool
1:6.1.170-213.321.amzn2023, 4.18.0-553.125.1.el8_10, 5.10.258-1.ph4, 5.15.0-320.202.8.5.el8uek, 5.15.0-320.202.8.5.el9uek, 5.15.0-321.202.5.el8uek, 5.15.0-321.202.5.el9uek, 6.1.177-1.ph5, 7.7.0+6.17.0-35.35, 7.7.0+7.0.0-22.22
bpftool6.12
1:6.12.83-115.161.amzn2023
bpftool6.18
1:6.18.25-57.109.amzn2023
cluster-md-kmp-64kb
6.12.0-160000.31.1
cluster-md-kmp-azure
6.12.0-160000.31.1
cluster-md-kmp-default
4.12.14-122.307.1, 5.14.21-150400.24.214.1, 5.14.21-150500.55.163.1, 6.12.0-160000.31.1, 6.4.0-150600.23.109.1, 6.4.0-150700.53.52.1, 6.4.0-150700.53.55.1
cluster-md-kmp-rt
6.12.0-160000.31.1, 6.4.0-150700.7.51.1
dlm-kmp-64kb
6.12.0-160000.31.1
dlm-kmp-azure
6.12.0-160000.31.1
dlm-kmp-default
4.12.14-122.307.1, 5.14.21-150400.24.214.1, 5.14.21-150500.55.163.1, 6.12.0-160000.31.1, 6.4.0-150600.23.109.1, 6.4.0-150700.53.52.1, 6.4.0-150700.53.55.1
dlm-kmp-rt
6.12.0-160000.31.1, 6.4.0-150700.7.51.1
dtb-allwinner
6.12.0-160000.31.1
dtb-altera
6.12.0-160000.31.1
dtb-amazon
6.12.0-160000.31.1
dtb-amd
6.12.0-160000.31.1
dtb-amlogic
6.12.0-160000.31.1
dtb-apm
6.12.0-160000.31.1
dtb-apple
6.12.0-160000.31.1
dtb-arm
6.12.0-160000.31.1
dtb-broadcom
6.12.0-160000.31.1
dtb-cavium
6.12.0-160000.31.1
dtb-exynos
6.12.0-160000.31.1
dtb-freescale
6.12.0-160000.31.1
dtb-hisilicon
6.12.0-160000.31.1
dtb-lg
6.12.0-160000.31.1
Timeline
Publicly disclosed
May 13, 2026
Added to Industry KEV feed
Aug 3, 2026
Last updated
Oct 16, 2026
Weakness Type
- CWE-123 Write-what-where Condition
- CWE-787 Out-of-bounds Write
References
- advisorycve.org · CVERecord
- advisorynvd.nist.gov · CVE-2026-46300
- advisorysecurity-tracker.debian.org · CVE-2026-46300
- advisoryubuntu.com · CVE-2026-46300
- advisoryRHBA-2026:20032
FAQ
Common Questions.
In the Linux kernel, the following vulnerability has been resolved: net: skbuff: preserve shared-frag marker during coalescing skb_try_coalesce() can attach paged frags from @from to @to.
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 Aug 3, 2026.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
A public exploit is reported by tracking sources, but no code link is listed yet.
Fixed versions are available, including bpftool 1:6.1.170-213.321.amzn2023, bpftool 4.18.0-553.125.1.el8_10, bpftool 5.10.258-1.ph4.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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