GHSA-8hp2-qmc6-f97h · Severity: high — In the Linux kernel, the following vulnerability has been resolved: smb: client: validate the...
In the Linux kernel, the following vulnerability has been resolved: smb: client: validate the whole DACL before rewriting it in cifsacl build_sec_desc() and id_mode_to_cifs_acl() derive a DACL pointer from a server-supplied dacloffset and then use the incoming ACL to rebuild the chmod/chown security descriptor. The original fix only checked that the struct smb_acl header fits before reading dacl_ptr->size or dacl_ptr->num_aces. That avoids the immediate header-field OOB read, but the rewrite helpers still walk ACEs based on pdacl->num_aces with no structural validation of the incoming DACL body. A malicious server can return a truncated DACL that still contains a header, claims one or more ACEs, and then drive replace_sids_and_copy_aces() or set_chmod_dacl() past the validated extent while they compare or copy attacker-controlled ACEs. Factor the DACL structural checks into validate_dacl(), extend them to validate each ACE against the DACL bounds, and use the shared validator before the chmod/chown rebuild paths. parse_dacl() reuses the same validator so the read-side parser and write-side rewrite paths agree on what constitutes a well-formed incoming DACL.
Conclusion & alert: CVE-2026-31709 is rated Moderate Risk (41.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Mandatory action: Review affected assets and schedule remediation.
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 | 2026-06-02 | 0.02% | 0.05% | +0.03% |
| 2 | 2026-05-02 | — | 0.02% | — |
Full EPSS history (2 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 8.8 | 3.1 | HIGH |
|
2.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
GHSA-8hp2-qmc6-f97h · Severity: high — In the Linux kernel, the following vulnerability has been resolved: smb: client: validate the...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
unimportant | CVE-2026-31709 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-2026-31709 |
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2026-31709 |
suse
|
high | — | https://www.suse.com/security/cve/CVE-2026-31709/ |
ubuntu
|
medium | CVE-2026-31709 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 169, needed 99, released 83, not-affected 45, needs-triage 4, pending 1. | https://ubuntu.com/security/CVE-2026-31709 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| linux | linux_kernel | >= 5.12, < 7.0.2 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |