VulnerabilityPublished 18 Oct 2026

CVE-2026-98827: Linux kernel · wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in e73a619f91b6cfec47bc1a94aea28df6849e5be3 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 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 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in e73a619f91b6cfec47bc1a94aea28df6849e5be3, c18882768a0fe253c70986c5fe66d9241570fbc4, aeaca27c1db3106967ffbb2b517d98c835f6d500 +1

Exploitation evidence

Disclosed: evidence found.
CVE published 18 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 Linux kernel to e73a619f91b6cfec47bc1a94aea28df6849e5be3, c18882768a0fe253c70986c5fe66d9241570fbc4, aeaca27c1db3106967ffbb2b517d98c835f6d500 or 345ce265cf604e84b5b560c21beaf4c6f269ab14.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ fb9987d0f748c983bb795a86f47522313f701a08, < e73a619f91b6cfec47bc1a94aea28df6849e5be3	Fixed in e73a619f91b6cfec47bc1a94aea28df6849e5be3
LinuxLinux	Affected ≥ fb9987d0f748c983bb795a86f47522313f701a08, < c18882768a0fe253c70986c5fe66d9241570fbc4	Fixed in c18882768a0fe253c70986c5fe66d9241570fbc4
LinuxLinux	Affected ≥ fb9987d0f748c983bb795a86f47522313f701a08, < aeaca27c1db3106967ffbb2b517d98c835f6d500	Fixed in aeaca27c1db3106967ffbb2b517d98c835f6d500
LinuxLinux	Affected ≥ fb9987d0f748c983bb795a86f47522313f701a08, < 345ce265cf604e84b5b560c21beaf4c6f269ab14	Fixed in 345ce265cf604e84b5b560c21beaf4c6f269ab14
LinuxLinux	Affected =2.6.35	Fixed in–

AI-suggested

A fix is available in the Linux kernel commits identified by hashes e73a619f91b6cfec47bc1a94aea28df6849e5be3, c18882768a0fe253c70986c5fe66d9241570fbc4, aeaca27c1db3106967ffbb2b517d98c835f6d500, and 345ce265cf604e84b5b560c21beaf4c6f269ab14. Users should update their Linux kernel to a version including these fixes to remediate the vulnerability.

Description

A vulnerability in the Linux kernel's ath9k_htc wifi driver allowed TX aggregation to exceed the allocated buffer size, causing a buffer overflow. This was due to the aggregation loop not limiting the cumulative byte length, leading to memory corruption when handling large frames. The issue was fixed by bounding the aggregation to the maximum buffer size and adjusting the buffer length accounting to prevent frame loss.

Impact

The vulnerability could lead to memory corruption in the kernel's wifi driver when transmitting large aggregated frames, potentially causing system instability or crashes. However, there is no indication of known exploitation in the wild. The impact is limited to devices using the affected ath9k_htc driver with large MTU settings.

Summary

The Linux kernel's ath9k_htc wifi driver had a flaw in the __hif_usb_tx() function where up to 20 frames could be aggregated into a single transmit buffer without limiting the total byte size. With large MTU frames (2304 bytes), this caused memcpy operations to write beyond the allocated buffer (32768 bytes), resulting in a buffer overflow of up to 13152 bytes. The fix involved limiting the aggregation loop to not exceed MAX_TX_BUF_SIZE and changing how the buffer length and offset are updated to ensure no oversized USB requests are submitted and no frames are silently dropped. Testing confirmed the fix prevents oversized URBs and maintains packet transmission integrity.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:43 UTC

Technical details

References

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