VulnerabilityPublished 23 Oct 2026Updated 26 Oct 2026

CVE-2026-98887: Linux kernel · wifi: mac80211_hwsim: reject undersized HWSIM_ATTR_TX_INFO

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in b5b1234bbfa25537fb9a5c0d62c328ed4547f721 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 12:55 UTC

Severity

Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b5b1234bbfa25537fb9a5c0d62c328ed4547f721, 59e1f2a0242232b4a3af144ae317d3913fc09046, 13edd8ea7ff2ce6a964b290ef2034cd8cbed96c7 +4

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < b5b1234bbfa25537fb9a5c0d62c328ed4547f721	Fixed in b5b1234bbfa25537fb9a5c0d62c328ed4547f721
LinuxLinux	Affected ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < 59e1f2a0242232b4a3af144ae317d3913fc09046	Fixed in 59e1f2a0242232b4a3af144ae317d3913fc09046
LinuxLinux	Affected ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < 13edd8ea7ff2ce6a964b290ef2034cd8cbed96c7	Fixed in 13edd8ea7ff2ce6a964b290ef2034cd8cbed96c7
LinuxLinux	Affected ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < 6f6368b20f8c9481fa7ba7b672dcb3c9f36b2695	Fixed in 6f6368b20f8c9481fa7ba7b672dcb3c9f36b2695
LinuxLinux	Affected ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < 3dc723ac78a6e4fa0fd49e27e487ed319da40a9f	Fixed in 3dc723ac78a6e4fa0fd49e27e487ed319da40a9f
LinuxLinux	Affected ≥ 5d44fe7c9808c56e136e59147bd932f5491520f1, < 3a96bb65b4b820d8b41fa155781ec1c29e3479d4	Fixed in 3a96bb65b4b820d8b41fa155781ec1c29e3479d4

AI-suggested

A fix is available in the Linux kernel. The vulnerability is resolved by requiring the exact length for the HWSIM_ATTR_TX_INFO attribute in the policy, preventing malformed attributes from being processed. Users should update to a fixed kernel version containing the relevant patches.

Description

A vulnerability in the Linux kernel's mac80211_hwsim component allows undersized HWSIM_ATTR_TX_INFO attributes to be accepted, leading to out-of-bounds reads. This occurs because the handler unconditionally reads a fixed number of entries without verifying the exact attribute length. The issue is fixed by enforcing exact length checks in the attribute policy.

Impact

The vulnerability results in out-of-bounds memory reads due to improper validation of the HWSIM_ATTR_TX_INFO attribute length. This could potentially lead to information disclosure or kernel instability. No known exploits in the wild have been reported.

Summary

The Linux kernel's mac80211_hwsim module contained a vulnerability where the function hwsim_tx_info_frame_received_nl() casts the HWSIM_ATTR_TX_INFO payload to a struct hwsim_tx_rate pointer and reads IEEE80211_TX_MAX_RATES entries unconditionally. The attribute length was only bounded from above, and strict validation was disabled, allowing short or zero-length attributes to be accepted. This caused out-of-bounds memory reads. The fix requires the attribute to have the exact expected length, rejecting malformed attributes before processing.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:32 UTC

Technical details

References

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