VulnerabilityPublished 27 May 2026Updated 6 Nov 2026

CVE-2026-45891: Linux kernel · net: hns3: fix double free issue for tx spare buffer

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in fdbccddb7e7822016601829f95de4008e193f7bc : patch Linux kernel soon.

Data as of 6 Nov 2026, 16:05 UTC

Severity

High

Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in fdbccddb7e7822016601829f95de4008e193f7bc, fb6a4c376d454b425555b1b0bda36e99f56ec307, d2c785733dfb853ea0b53984c75662a1af230a94 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 27 May 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 6 Nov 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.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < fdbccddb7e7822016601829f95de4008e193f7bc	Fixed in fdbccddb7e7822016601829f95de4008e193f7bc
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < fb6a4c376d454b425555b1b0bda36e99f56ec307	Fixed in fb6a4c376d454b425555b1b0bda36e99f56ec307
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < d2c785733dfb853ea0b53984c75662a1af230a94	Fixed in d2c785733dfb853ea0b53984c75662a1af230a94
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < c3659273860bed0c8e573b865e3769abc51225a8	Fixed in c3659273860bed0c8e573b865e3769abc51225a8
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < 43015461662d41dcfb3bb95fadd8a2a42ad8eacf	Fixed in 43015461662d41dcfb3bb95fadd8a2a42ad8eacf
LinuxLinux	Affected ≥ 907676b130711fd1f627824559e92259db2061d1, < 6dc10494cfe27b6f1e9adb7e293293ae39c50b7c	Fixed in 6dc10494cfe27b6f1e9adb7e293293ae39c50b7c

AI-suggested

A patch is available and has been applied in the Linux kernel. Users running version 5.14 should update to a fixed kernel version containing the commits identified by the provided fixedVersions hashes. Since this is a kernel-level issue, applying the official kernel update is the recommended remediation.

Description

CVE-2026-45891 is a vulnerability in the Linux kernel's hns3 network driver where a double-free error occurs due to improper handling of the tx_spare buffer pointer during ring parameter setting. This flaw arises when the tx_spare pointer is not cleared after a failed memory allocation, causing the error cleanup path to free the same memory twice. The issue affects Linux kernel version 5.14 and has been fixed by setting the tx_spare pointer to NULL upon failure to prevent erroneous freeing.

Impact

The double-free vulnerability can lead to undefined behavior such as kernel crashes or potential memory corruption, which may be exploitable to compromise system stability or security. However, no known exploits in the wild have been reported for this issue.

Summary

The vulnerability occurs in the hns3_set_ringparam() function of the Linux kernel's hns3 network driver. A temporary copy of the ring structure is created for rollback, but the tx_spare pointer in the original ring structure remains pointing to old backup memory. If memory allocation fails later during ring initialization, the error path attempts to free all newly allocated buffers, mistakenly including the stale tx_spare pointer, resulting in a double-free of the backup memory. The fix involves clearing the tx_spare pointer to NULL when creation of a new tx_spare buffer fails, ensuring only newly allocated buffers are freed.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 6 Nov 2026, 16:05 UTC

Technical details

References

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