CVE-2026-31671
xfrm_user: fix info leak in build_report()
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm_user: fix info leak in build_report() struct xfrm_user_report is a __u8 proto field followed by a struct xfrm_selector which means there is three "empty" bytes of padding, but the padding is never zeroed before copying to userspace. Fix that up by zeroing the structure before setting individual member variables.
INFO
Published Date :
April 24, 2026, 3:16 p.m.
Last Modified :
April 27, 2026, 8:11 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Zero the structure before setting members.
- Apply the kernel patch for xfrm_user_report.
Public PoC/Exploit Available at Github
CVE-2026-31671 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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-2026-31671.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31671 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-2026-31671
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).
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31671 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31671 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.
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Initial Analysis by [email protected]
Apr. 27, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-401 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:2.6.19:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.11 up to (excluding) 5.15.203 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.16 up to (excluding) 6.1.169 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.23 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 6.19.13 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.135 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.82 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 2.6.19.1 up to (excluding) 5.10.253 Added Reference Type kernel.org: https://git.kernel.org/stable/c/0616314b3b34f24cbb91da8c6bd8bcdc4c8592f9 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/0a30dceb0e1f0c480d2482e6d7cebf8aebb6eb72 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/6c55714c931051cd7f4839c19ce0867179fd22fe Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/716c546e88cfe49d841658240e10cb57bc50a2cc Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d10119968d0e1f2b669604baf2a8b5fdb72fa6b4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/d27c02eec529f78055a46a5c9e6c62684382b2d8 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/e0c8542c3d097ed4205ded51868195d5d6ddac62 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/ff5ee507302303b15859753c3e0d67d38fd12c88 Types: Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 24, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: xfrm_user: fix info leak in build_report() struct xfrm_user_report is a __u8 proto field followed by a struct xfrm_selector which means there is three "empty" bytes of padding, but the padding is never zeroed before copying to userspace. Fix that up by zeroing the structure before setting individual member variables. Added Reference https://git.kernel.org/stable/c/0616314b3b34f24cbb91da8c6bd8bcdc4c8592f9 Added Reference https://git.kernel.org/stable/c/0a30dceb0e1f0c480d2482e6d7cebf8aebb6eb72 Added Reference https://git.kernel.org/stable/c/6c55714c931051cd7f4839c19ce0867179fd22fe Added Reference https://git.kernel.org/stable/c/716c546e88cfe49d841658240e10cb57bc50a2cc Added Reference https://git.kernel.org/stable/c/d10119968d0e1f2b669604baf2a8b5fdb72fa6b4 Added Reference https://git.kernel.org/stable/c/d27c02eec529f78055a46a5c9e6c62684382b2d8 Added Reference https://git.kernel.org/stable/c/e0c8542c3d097ed4205ded51868195d5d6ddac62 Added Reference https://git.kernel.org/stable/c/ff5ee507302303b15859753c3e0d67d38fd12c88