HOMEVULNERABILITIESCVE-2026-31609
CRITICAL

CVE-2026-31609

Published: April 24, 2026· Updated: Apr 29, 2026

9.8
CVSS v3.1
EPSS:0.02%probability of exploitation in 30 daysPercentile:4.6th

Official Description

In the Linux kernel, the following vulnerability has been resolved:

smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()

smbd_send_batch_flush() already calls smbd_free_send_io(),

so we should not call it again after smbd_post_send()

moved it to the batch list.

NVD Source

Technical Analysis

CVE-2026-31609 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Linux1 product
linux kernel
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

PATCHhttps://git.kernel.org/stable/c/22b7c1c619d808aec4cad3dc42103345e370d107
PATCHhttps://git.kernel.org/stable/c/27b7c3e916218b5eb2ee350211140e961bfc49be
PATCHhttps://git.kernel.org/stable/c/a9940dcbe5cb92482c04efc7341039ddf7dbf607
PATCHhttps://git.kernel.org/stable/c/f9a162c2bbcd0ac85bd07c5b37cf20286048b65c

All References (4)

→
https://git.kernel.org/stable/c/22b7c1c619d808aec4cad3dc42103345e370d107Patch
→
https://git.kernel.org/stable/c/27b7c3e916218b5eb2ee350211140e961bfc49bePatch
→
https://git.kernel.org/stable/c/a9940dcbe5cb92482c04efc7341039ddf7dbf607Patch
→
https://git.kernel.org/stable/c/f9a162c2bbcd0ac85bd07c5b37cf20286048b65cPatch

Quick Facts

CVE IDCVE-2026-31609
CVSS Score9.8 / 10
SeverityCRITICAL
CISA KEVNo
EPSS (30d)0.02%
Affected1 vendor
PublishedApr 24, 2026

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2026-31609 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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