CVE Catalog

CVE-2026-53395

HighCVSS 7.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.34%

27th percentile - higher than 27% of all known CVEs

Summary

In the Linux kernel NFSD subsystem, a dead ACL conflict guard in nfsd4_create() checked nulled pointers instead of stolen values, causing memory leak of posix_acl objects when both ACL and POSIX ACL attributes are requested in the same CREATE operation.

Risk Assessment

The organization is at risk of kernel slab exhaustion via repeated crafted CREATE requests, potentially leading to denial of service (DoS) on the NFS server.

Recommendation

Immediately update the Linux kernel to a version containing the fix (commit that removes dead code and checks attrs.na_dpacl/na_pacl). As a workaround, restrict NFS server access to trusted clients only.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix dead ACL conflict guard in nfsd4_create nfsd4_create() steals create->cr_dpacl/cr_pacl into the local nfsd_attrs via the designated initializer, then immediately sets the source pointers to NULL. The subsequent conflict guard tests the already-nilled source fields, making it permanently dead code: if (create->cr_acl) { if (create->cr_dpacl || create->cr_pacl) /* always false */ When a client encodes both FATTR4_WORD0_ACL and FATTR4_WORD2_POSIX_{DEFAULT,ACCESS}_ACL in the same CREATE fattr bitmap, nfsd4_acl_to_attr() overwrites attrs.na_pacl/na_dpacl without releasing the originals, leaking two posix_acl slab objects per request. Repeated requests cause unbounded slab exhaustion. Fix by checking attrs.na_dpacl/na_pacl (the stolen values) instead of the nilled create->cr_dpacl/cr_pacl, matching the correct pattern already used in nfsd4_setattr().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS