In the Linux kernel, the following vulnerability has been resolved: net: ipv6: fix field-spanning memcpy warning in AH output Fix field-spanning memcpy warnings in ah6_output() and ah6_output_done() where extension headers are copied to/from IPv6 address fields, triggering fortify-string warnings about writes beyond the 16-byte address fields. memcpy: detected field-spanning write (size 40) of single field "&top_iph->saddr" at net/ipv6/ah6.c:439 (size 16) WARNING: CPU: 0 PID: 8838 at net/ipv6/ah6.c:439 ah6_output+0xe7e/0x14e0 net/ipv6/ah6.c:439 The warnings are false positives as the extension headers are intentionally placed after the IPv6 header in memory. Fix by properly copying addresses and extension headers separately, and introduce helper functions to avoid code duplication.
Conclusion & alert: CVE-2025-40363 is rated Low Risk (18.1/100): low exploitation likelihood (EPSS 0.06%). 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.
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 | 2026-05-26 | 0.04% | 0.06% | +0.01% |
| 2 | 2026-05-14 | 0.06% | 0.04% | -0.02% |
| 3 | 2026-01-18 | — | 0.06% | — |
Full EPSS history (4 records total)
CVSS metrics for this CVE.
No CVSS data in dataset for this CVE.
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-40363 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2025-40363 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-40363 |
suse
|
low | CVE-2025-40363 severity low: SUSE including 386 source package names (13.2-9.1:libsqlite3-0-3.49.1-1.1, 2.1.3-6.115:kernel-default-base-6.4.0-39.1.21.16, …), 588 product×package rows across 69 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (69 product lines)): Fixed 332, Known Affected 231, First Fixed 25. | https://www.suse.com/security/cve/CVE-2025-40363/ |
ubuntu
|
medium | CVE-2025-40363 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 157, needed 50, not-affected 3, pending 3. | https://ubuntu.com/security/CVE-2025-40363 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||