CVE-2026-63912
xfrm: esp: restore combined single-frag length gate
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.
INFO
Published Date :
July 19, 2026, 4:17 p.m.
Last Modified :
July 27, 2026, 5:44 p.m.
Remotely Exploit :
Yes !
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | CRITICAL | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest patched version.
- Ensure ESP trailer handling is correctly restored.
- Verify combined length page gates are functional.
- Apply relevant IPv4 and IPv6 patches.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63912.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63912 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63912
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63912 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63912 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'c075c3ea031757f8ea2d34567565b61a868c08d5', 'lessThan': '566295735530ee513326049b0540f32ec050bf2e', 'versionType': 'git'}, {'status': 'affected', 'version': 'a583f2f3c8788bffd7fd7baeb76bd6d80543d7ea', 'lessThan': '5d7ab86e2b6bc23054616bf6ac562013bf60af8c', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': '36519e3d941fc99d3b52c134dbaf311f987a4708', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': '322e48187e0245ab2fff6fec2220b0cae677dbec', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': 'b84091ceddc9f133229dceab3ccc930bf27f9cba', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': 'c093468aea8277f77272a4f199b2e15e19cabb59', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': '65f3b3fc2347b89fe21db1e92c7681368415f095', 'versionType': 'git'}, {'status': 'affected', 'version': '5bd8baab087dff657e05387aee802e70304cc813', 'lessThan': 'dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40', 'versionType': 'git'}, {'status': 'affected', 'version': '2c66b0c95bb0aa7652ba1eba293d0d5993b35a38', 'versionType': 'git'}, {'status': 'affected', 'version': 'ef6f83df1209a7d9bd1c605a62457d4c00f9179e', 'versionType': 'git'}, {'status': 'affected', 'version': '3defefd22ad5fbbe639b6157fb7e6311b2bf333d', 'versionType': 'git'}, {'status': 'affected', 'version': 'b657030870bb5351c5b1e84d4e9f186da6ca0496', 'versionType': 'git'}, {'status': 'affected', 'version': '5.10.113', 'lessThan': '5.10.259', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.15.36', 'lessThan': '5.15.210', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.14.288', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'affected', 'version': '4.19.252', 'lessThan': '4.20', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.4.205', 'lessThan': '5.5', 'versionType': 'semver'}, {'status': 'affected', 'version': '5.17.5', 'lessThan': '5.18', 'versionType': 'semver'}], 'programFiles': ['net/ipv4/esp4.c', 'net/ipv6/esp6.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.18'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.18', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.259', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.210', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.176', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.143', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.93', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.35', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.12', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/esp4.c', 'net/ipv6/esp6.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/322e48187e0245ab2fff6fec2220b0cae677dbec Added Reference https://git.kernel.org/stable/c/36519e3d941fc99d3b52c134dbaf311f987a4708 Added Reference https://git.kernel.org/stable/c/566295735530ee513326049b0540f32ec050bf2e Added Reference https://git.kernel.org/stable/c/5d7ab86e2b6bc23054616bf6ac562013bf60af8c Added Reference https://git.kernel.org/stable/c/65f3b3fc2347b89fe21db1e92c7681368415f095 Added Reference https://git.kernel.org/stable/c/b84091ceddc9f133229dceab3ccc930bf27f9cba Added Reference https://git.kernel.org/stable/c/c093468aea8277f77272a4f199b2e15e19cabb59 Added Reference https://git.kernel.org/stable/c/dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40