CVE-2026-93811 — ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling
In the Linux kernel, the following vulnerability has been resolved: ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling 1. When ndr_decode_v4_ntacl() fails, the code jumped to free_n_data which only freed n.data, skipping kfree(acl.sd_buf) and leaking the buffer. Zero-initialize struct xattr_ntacl acl, reorder error labels to out_free to release acl.sd_buf on all error paths. 2. if (acl.sd_size < sizeof(struct smb_ntsd)) is true, original code returned success without freeing sd_buf and left stale *pntsd. Set rc = -EINVAL before jumping to out_free to return error code and free buffer.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ cb69d4d6f709f87c94afa28ae64c501576692171 and < f46a70a082bdbfecbe074af8a719c26c4deb58c6≥ 8f0541186e9ad1b62accc9519cc2b7a7240272a7 and < 86c2625fb9863139b359805fc6be1e31edbd3d65≥ 8f0541186e9ad1b62accc9519cc2b7a7240272a7 and < edc17db83085624a2b1bacf6a4521d7f15571737≥ 8f0541186e9ad1b62accc9519cc2b7a7240272a7 and < c3836f55e0dab96314774215e12d87f63fa919f2≥ 8f0541186e9ad1b62accc9519cc2b7a7240272a7 and < 6e6329322ad733c5b23555c609353841560b26bc≥ 8f0541186e9ad1b62accc9519cc2b7a7240272a7 and < d708a36634bb7b6f94d0e76d587d2ec50b2b93b5version 6e8f4abf584253cbaa596ea4ad13110cf61cd4c9version 8e33102309bd6839b2e2e158f93a7b378cb4655d and 4 more≥ 5.15.62 and < 5.15.222≥ 5.18.18 and < 5.19≥ 5.19.2 and < 5.20version 6.0 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 16, 2026 · 2 reading(s) · max 0.17%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
6 on the record
- git.kernel.org/stable/c/edc17db83085624a2b1bacf6a4521d7f15571737
- git.kernel.org/stable/c/c3836f55e0dab96314774215e12d87f63fa919f2
- git.kernel.org/stable/c/6e6329322ad733c5b23555c609353841560b26bc
- git.kernel.org/stable/c/d708a36634bb7b6f94d0e76d587d2ec50b2b93b5
- git.kernel.org/stable/c/86c2625fb9863139b359805fc6be1e31edbd3d65
- git.kernel.org/stable/c/f46a70a082bdbfecbe074af8a719c26c4deb58c6
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 2d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 2d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 3d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 3d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 3d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 3d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-93811 is "ksmbd: Fix acl.sd_buf memory leak and invalid sd_size error handling", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.17% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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