GHSA-vh2p-4gfm-v9v7 · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: kernel: be more careful...
In the Linux kernel, the following vulnerability has been resolved: kernel: be more careful about dup_mmap() failures and uprobe registering If a memory allocation fails during dup_mmap(), the maple tree can be left in an unsafe state for other iterators besides the exit path. All the locks are dropped before the exit_mmap() call (in mm/mmap.c), but the incomplete mm_struct can be reached through (at least) the rmap finding the vmas which have a pointer back to the mm_struct. Up to this point, there have been no issues with being able to find an mm_struct that was only partially initialised. Syzbot was able to make the incomplete mm_struct fail with recent forking changes, so it has been proven unsafe to use the mm_struct that hasn't been initialised, as referenced in the link below. Although 8ac662f5da19f ("fork: avoid inappropriate uprobe access to invalid mm") fixed the uprobe access, it does not completely remove the race. This patch sets the MMF_OOM_SKIP to avoid the iteration of the vmas on the oom side (even though this is extremely unlikely to be selected as an oom victim in the race window), and sets MMF_UNSTABLE to avoid other potential users from using a partially initialised mm_struct. When registering vmas for uprobe, skip the vmas in an mm that is marked unstable. Modifying a vma in an unstable mm may cause issues if the mm isn't fully initialised.
Conclusion & alert: CVE-2025-21709 is rated Low Risk (26.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Mandatory action: 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.
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 | 0.05% | 0.04% | -0.01% |
| 2 | 2026-05-17 | 0.04% | 0.05% | +0.01% |
| 3 | 2025-10-24 | — | 0.04% | — |
Full EPSS history (5 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.5 | 3.1 | MEDIUM |
|
1.8 | 3.6 | [email protected] |
GHSA-vh2p-4gfm-v9v7 · Severity: medium — In the Linux kernel, the following vulnerability has been resolved: kernel: be more careful...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2025-21709 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-2025-21709 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-21709 |
suse
|
medium | CVE-2025-21709 severity moderate: SUSE including 52 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 273 product×package rows across 48 product lines (SLES-LTSS-TERADATA 15 SP2, SUSE Linux Enterprise High Availability Extension 12 SP5, … (48 product lines)): Known Not Affected 247, Fixed 26. | https://www.suse.com/security/cve/CVE-2025-21709/ |
ubuntu
|
medium | CVE-2025-21709 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 165, not-affected 116, released 92, needed 33. | https://ubuntu.com/security/CVE-2025-21709 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | >= 6.8, < 6.13.2 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |