A vulnerability in the Linux kernel's bareudp driver causes a NULL pointer dereference in the function bareudp_fill_metadata_dst(). (CVE-2026-45846)
A vulnerability in the Linux kernel's bareudp driver causes a NULL pointer dereference in the function bareudp_fill_metadata_dst(). This occurs because the function calls udp_tunnel6_dst_lookup() with a socket pointer that may be NULL if the device is down. The issue triggers a kernel crash (NULL pointer dereference) when the socket is not initialized. The vulnerability has been fixed by adding a NULL check that returns an error code when the socket is NULL.
AI Analysis
Technical Summary
The Linux kernel bareudp driver had a vulnerability (CVE-2026-45846) where bareudp_fill_metadata_dst() called udp_tunnel6_dst_lookup() passing bareudp->sock without verifying if it was NULL. Since the socket is only created in bareudp_open() and set to NULL in bareudp_stop(), invoking this function while the device is down leads to a NULL pointer dereference and kernel crash. The fix involves adding a NULL check returning -ESHUTDOWN to prevent the dereference, aligning with existing transmit path checks in the driver.
Potential Impact
This vulnerability results in a denial of service via a kernel NULL pointer dereference, causing the affected system to crash. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability description indicates a fix has been implemented by adding a NULL check, but no explicit patch link or official fix advisory is provided. Users should monitor the Microsoft Security Response Center or Linux kernel updates for the official patch and apply it once available.
A vulnerability in the Linux kernel's bareudp driver causes a NULL pointer dereference in the function bareudp_fill_metadata_dst(). (CVE-2026-45846)
Description
A vulnerability in the Linux kernel's bareudp driver causes a NULL pointer dereference in the function bareudp_fill_metadata_dst(). This occurs because the function calls udp_tunnel6_dst_lookup() with a socket pointer that may be NULL if the device is down. The issue triggers a kernel crash (NULL pointer dereference) when the socket is not initialized. The vulnerability has been fixed by adding a NULL check that returns an error code when the socket is NULL.
CVSS v3.1
Score 5.5medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The Linux kernel bareudp driver had a vulnerability (CVE-2026-45846) where bareudp_fill_metadata_dst() called udp_tunnel6_dst_lookup() passing bareudp->sock without verifying if it was NULL. Since the socket is only created in bareudp_open() and set to NULL in bareudp_stop(), invoking this function while the device is down leads to a NULL pointer dereference and kernel crash. The fix involves adding a NULL check returning -ESHUTDOWN to prevent the dereference, aligning with existing transmit path checks in the driver.
Potential Impact
This vulnerability results in a denial of service via a kernel NULL pointer dereference, causing the affected system to crash. There is no indication of confidentiality or integrity impact. No known exploits are reported in the wild.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. The vulnerability description indicates a fix has been implemented by adding a NULL check, but no explicit patch link or official fix advisory is provided. Users should monitor the Microsoft Security Response Center or Linux kernel updates for the official patch and apply it once available.
Technical Details
- Gcve Source
- db.gcve.eu
- Csaf Category
- csaf_vex
- Csaf Version
- 2.0
- Publisher
- Microsoft Security Response Center
- Advisory Id
- msrc_CVE-2026-45846
- Cve Count
- 1
- Additional Cves
- []
- Cvss Version
- 3.1
Threat ID: 6a18ab8ae29bf47b50289124
Added to database: 05/28/2026, 20:54:34 UTC
Last enriched: 06/26/2026, 23:39:25 UTC
Last updated: 07/31/2026, 19:22:59 UTC
Views: 58
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