CVE-2026-43497 | fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free

In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: add vm_ops to dlfb_ops_mmap to prevent use-after-free dlfb_ops_mmap() uses remap_pfn_range() to map vmalloc framebuffer pages to userspace but sets no vm_ops on the VMA. This means the kernel cannot track active mmaps. When dlfb_realloc_framebuffer() replaces the backing buffer via FBIOPUT_VSCREENINFO, existing mmap PTEs are not invalidated. On USB disconnect, dlfb_ops_destroy() calls vfree() on the old pages while userspace PTEs still reference them, resulting in a use-after-free: the process retains read/write access to freed kernel pages. Add vm_operations_struct with open/close callbacks that maintain an atomic mmap_count on struct dlfb_data. In dlfb_realloc_framebuffer(), check mmap_count and return -EBUSY if the buffer is currently mapped, preventing buffer replacement while userspace holds stale PTEs. Tested with PoC using dummy_hcd + raw_gadget USB device emulation.

Published: 2026-05-21 Last update: 2026-06-01 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD Status：Awaiting Analysis，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-43497 is rated Low Risk (31/100): CVSS High severity, with low exploitation likelihood (EPSS 0.02%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-43497

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-22 — 0.02% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-43497

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.3 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.3 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Weakness enumeration for CVE-2026-43497

GitHub Security Advisory for CVE-2026-43497

GHSA-233x-r9gj-mfg9 · Severity: high — In the Linux kernel, the following vulnerability has been resolved: fbdev: udlfb: add vm_ops to...

OS Trackers for CVE-2026-43497

vendor priority summary link
debian not yet assigned CVE-2026-43497 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 3, open 2. https://security-tracker.debian.org/tracker/CVE-2026-43497
redhat — — https://access.redhat.com/security/cve/CVE-2026-43497
suse high CVE-2026-43497 severity important: SUSE including 15 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 39 product×package rows across 10 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise Live Patching 15 SP7, … (10 product lines)): Known Not Affected 39. https://www.suse.com/security/cve/CVE-2026-43497/
ubuntu medium CVE-2026-43497 medium priority: Ubuntu including 161 source packages (linux, linux-allwinner-5.19, …), 1449 status rows across 9 suites (bionic, focal, jammy, noble, questing, resolute, trusty, upstream, xenial): DNE 1048, ignored 173, needed 141, released 87. https://ubuntu.com/security/CVE-2026-43497

Affected software / configurations for CVE-2026-43497

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-43497

cvelogic Threat Intelligence