In the Linux kernel, the following vulnerability has been resolved: crypto: comp - Use same definition of context alloc and free ops In commit 42d9f6c77479 ("crypto: acomp - Move scomp stream allocation code into acomp"), the crypto_acomp_streams struct was made to rely on having the alloc_ctx and free_ctx operations defined in the same order as the scomp_alg struct. But in that same commit, the alloc_ctx and free_ctx members of scomp_alg may be randomized by structure layout randomization, since they are contained in a pure ops structure (containing only function pointers). If the pointers within scomp_alg are randomized, but those in crypto_acomp_streams are not, then the order may no longer match. This fixes the problem by removing the union from scomp_alg so that both crypto_acomp_streams and scomp_alg will share the same definition of alloc_ctx and free_ctx, ensuring they will always have the same layout.
Conclusion & alert: CVE-2025-40063 is rated Low Risk (3.4/100): 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.
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 | 2025-10-28 | — | 0.02% | — |
Full EPSS history (1 record total)
CVSS metrics for this CVE.
No CVSS data in dataset for this CVE.
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2025-40063 unimportant priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. | https://security-tracker.debian.org/tracker/CVE-2025-40063 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-40063 |
suse
|
medium | CVE-2025-40063 severity moderate: SUSE including 30 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 273 product×package rows across 54 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 15 SP7, … (54 product lines)): Known Not Affected 269, Fixed 4. | https://www.suse.com/security/cve/CVE-2025-40063/ |
ubuntu
|
medium | CVE-2025-40063 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 159, not-affected 136, released 98, needed 2. | https://ubuntu.com/security/CVE-2025-40063 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| No affected products in dataset. | |||