CVE-2026-43284: Linux kernel · xfrm: esp: avoid in-place decrypt on shared skb frags
Affects Linux kernelSource GCVE Database
Public exploit available (Metasploit, Exploit-DB) · 94% EPSS · CVSS 8.8 High · fixed in 4.15.0-1202.217~14.04.1 : patch Linux kernel as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 94.1% chance of exploitation in 30 days – higher than 99% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.15.0-1202.217~14.04.1, 4.15.0-1194.207~16.04.1, 4.15.0-251.263 +117
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:HExploitation evidence
t = 0 is the CVE’s publication on cve.org
Disclosed: evidence found.
CVE published 8 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: evidence found.
1 Metasploit module · 2 Exploit-DB entries, the first 19 days after disclosure
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
Timeline
CVE published
on cve.org
, t = 0
First Exploit-DB entry (opens in a new tab)
Linux Kernel - Local Privilege Escalation +1 more
, 19 days after disclosure
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-8370-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8371-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8373-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8374-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8391-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8392-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8426-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8426-2 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Ubuntu 26.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?arch=source&distro=resoluteOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
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().
References
- ubuntu.com/security/CVE-2026-43284 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-43284 (opens in a new tab)
- openwall.com/lists/oss-security/2026/05/08/7 (opens in a new tab)
- openwall.com/lists/oss-security/2026/05/07/8 (opens in a new tab)
- ubuntu.com/blog/dirty-frag-linux-vulnerability-fixes-available (opens in a new tab)
- github.com/0xdeadbeefnetwork/Copy_Fail2-Electric_Boogaloo/tree/main (opens in a new tab)
- github.com/V4bel/dirtyfrag (opens in a new tab)
- git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=f4c50a4034e62ab75f1d5cdd191dd5f9c77fdff4 (opens in a new tab)
- ubuntu.com/security/notices/USN-8370-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8371-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8373-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8374-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8391-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8392-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8393-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8426-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8426-2 (opens in a new tab)