VulnerabilityPublished 6 Oct 2026Updated 30 Oct 2026

CVE-2026-98170: Linux kernel · smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs()

Source GCVE Database

Compare

Authoritative record:CVE-2026-98170· Medium

Not known to be exploited · fixed in eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb : update Linux kernel when convenient.

Data as of 30 Oct 2026, 17:18 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

Thin evidence

One scorer or none

Patch: Available – fixed in eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb, d3546cecbf81d98bf3b472d341f981eb48c04f47, 61812323c037a94e2e7f0db7ee740c34b126bffe +5

Exploitation evidence

Disclosed: evidence found.
CVE published 6 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-qx7m-524h-7684

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb	Fixed in eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < d3546cecbf81d98bf3b472d341f981eb48c04f47	Fixed in d3546cecbf81d98bf3b472d341f981eb48c04f47
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < 61812323c037a94e2e7f0db7ee740c34b126bffe	Fixed in 61812323c037a94e2e7f0db7ee740c34b126bffe
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < 22886b1b7464613373c9a7d0af2ace029c50cd97	Fixed in 22886b1b7464613373c9a7d0af2ace029c50cd97
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < 90a13af4c9b1369327395bababfe87c75599cc19	Fixed in 90a13af4c9b1369327395bababfe87c75599cc19
LinuxLinux	Affected ≥ 95907fea4fd8ccc736e0a428e52159b4d42b9958, < 34a3942e787b9c59758115bd65fe1ec89d68c7a4	Fixed in 34a3942e787b9c59758115bd65fe1ec89d68c7a4

AI-suggested

A fix is available that adds proper bounds checking in the move_smb2_ea_to_cifs() function to prevent out-of-bounds reads. Users should apply the updated Linux kernel version containing this patch. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel SMB client was fixed to prevent out-of-bounds (OOB) reads in the move_smb2_ea_to_cifs() function. The issue arose because the loop condition allowed reading beyond the buffer when processing SMB2 extended attribute (EA) structures. The fix adds checks to ensure sufficient buffer size before reading and rejects malformed entries that could cause OOB reads. This change also updates error codes returned to userspace to more accurately reflect protocol errors.

Impact

Out-of-bounds reads in kernel code can lead to information disclosure or kernel instability. In this case, the vulnerability could cause the SMB client to read beyond the intended buffer when processing extended attributes, potentially leading to memory corruption or crashes. The update also improves error reporting to userspace, helping to correctly identify server protocol errors.

Summary

The Linux kernel SMB client contained a vulnerability in the move_smb2_ea_to_cifs() function where the loop iterating over SMB2 extended attribute structures did not properly validate the remaining buffer size before reading structure fields. This allowed out-of-bounds reads of ea_name_length and ea_value_length fields. The fix ensures that the remaining source size is at least the size of the structure before any reads and rejects next_entry_offset values that are too small or would advance beyond the buffer. Additionally, error codes returned to userspace were corrected to indicate server protocol errors rather than misleading conditions.

References

Community reviews

Loading reviews…