Critical severity · published Jul 19, 2026
CVE-2026-63912
xfrm: esp: restore combined single-frag length gate
9.8
CVSS
0.7%
EPSS
No
On KEV
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: restore combined single-frag length gate The ESP out-of-place fast path appends the trailer in esp_output_head() before esp_output_tail() allocates the destination page frag. The head-side gate currently checks skb->data_len and tailen separately, but the tail code allocates a single destination frag from the combined post-trailer skb->data_len. Reject the page-frag fast path when the combined aligned length exceeds a page. Otherwise skb_page_frag_refill() may fall back to a single page while the destination sg still spans the combined skb->data_len. Restore this combined-length page gate for both IPv4 and IPv6.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LI
Linux · Linux
c075c3ea031757f8ea2d34567565b61a868c08d5 before 566295735530ee513326049b0540f32ec050bf2e; a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea before 5d7ab86e2b6bc23054616bf6ac562013bf60af8c; 5bd8baab087dff657e05387aee802e70304cc813 before 36519e3d941fc99d3b52c134dbaf311f987a4708; 5bd8baab087dff657e05387aee802e70304cc813 before 322e48187e0245ab2fff6fec2220b0cae677dbec; 5bd8baab087dff657e05387aee802e70304cc813 before b84091ceddc9f133229dceab3ccc930bf27f9cba; 5bd8baab087dff657e05387aee802e70304cc813 before c093468aea8277f77272a4f199b2e15e19cabb59; +13 more · source: vendor