CVE-2025-40268 | cifs: client: fix memory leak in smb3_fs_context_parse_param

In the Linux kernel, the following vulnerability has been resolved: cifs: client: fix memory leak in smb3_fs_context_parse_param The user calls fsconfig twice, but when the program exits, free() only frees ctx->source for the second fsconfig, not the first. Regarding fc->source, there is no code in the fs context related to its memory reclamation. To fix this memory leak, release the source memory corresponding to ctx or fc before each parsing. syzbot reported: BUG: memory leak unreferenced object 0xffff888128afa360 (size 96): backtrace (crc 79c9c7ba): kstrdup+0x3c/0x80 mm/util.c:84 smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444 BUG: memory leak unreferenced object 0xffff888112c7d900 (size 96): backtrace (crc 79c9c7ba): smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629 smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438

Published: 2025-12-06 Last update: 2026-04-15 Assigner: 416baaa9-dc9f-4396-8d5f-8c081fb06d67 Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Conclusion & alert: CVE-2025-40268 is rated Low Risk (4.6/100): low exploitation likelihood (EPSS 0.02%). Mandatory action: Low composite risk—no urgent action required; patch on your normal maintenance cycle and revisit priority if CVSS or EPSS increases.

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-2025-40268

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 2025-12-07 0.02%

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-40268

CVSS metrics for this CVE.

No CVSS data in dataset for this CVE.

Weakness enumeration for CVE-2025-40268

OS Trackers for CVE-2025-40268

vendor priority summary link
debian unimportant CVE-2025-40268 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2025-40268
redhat low https://access.redhat.com/security/cve/CVE-2025-40268
suse medium CVE-2025-40268 severity moderate: SUSE including 403 source package names (13.2-9.1:libsystemd0-254.23-1.1, 13.2-9.1:libudev1-254.23-1.1, …), 786 product×package rows across 126 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (126 product lines)): Fixed 431, Known Affected 231, Known Not Affected 99, First Fixed 25. https://www.suse.com/security/cve/CVE-2025-40268/
ubuntu medium CVE-2025-40268 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 182, released 126, needed 82, not-affected 3, pending 2. https://ubuntu.com/security/CVE-2025-40268

Affected software / configurations for CVE-2025-40268

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2025-40268

cvelogic Threat Intelligence