CVE-2026-53397: linux
Vulnerability summary
CVE-2026-53397 is a high (CVSS 7.5) vulnerability in linux. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.5% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 38 · Related 33Timeline
- 19-07-2026PublishedVulnerability first disclosed.
- 16-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: nfsd: fix posix_acl leak on SETACL decode failure nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling. ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure: svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */ The orphaned posix_acl is leaked for the lifetime of the server. Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.53%
Chance of exploitation in the next 30 days
Percentile
44%
Versus all other CVEs
30-day change
0.00 pp
From 0.53% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu169 products
- linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-147.147 | < 7.0.0-31.31
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1067.70 | < 7.0.0-1012.12
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < b2eb1ffd511d1b3c3e21122f97cbbccea411e277 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < b94c4be77682aab06d65ca7296149e3bcfb37353 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < 887f92ceccf3eacd5f2402db21254d66372fae00 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < 1e96239fddcefacf6afe6c498357be68eacbcabc | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < bd69a825485168ef74e815ecb286754b570fdcc7 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < 136b416593f1349cf6f72c8e3d18f0f204ee8545 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < a5b42c1e4ff2befaa6b96f7cbf32174751eba083 | ≥ a257cdd0e2179630d3201c32ba14d7fcb3c3a055, < 0853ac544c590880d797b04daa33fcb72b6be0e1 | 2.6.13
- linux_kernel≥ 2.6.13, < 5.10.260 | ≥ 5.11, < 5.15.211 | ≥ 5.16, < 6.1.177 | ≥ 6.2, < 6.6.144 | ≥ 6.7, < 6.12.95 | ≥ 6.13, < 6.18.38 | ≥ 6.19, < 7.1.3
Debian1 product
- linux< 6.1.177-1 | < 6.12.95-1 | < 7.1.3-1
3 vendors · 172 products
