CVE-2026-68373: Linux kernel · wifi: at76c50x-usb: avoid length underflow in at76_guess_freq()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 8.1 High · fixed in fb1b50ab699211e777dca5ccfb648788b6a6e519 : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- CISA SSVC
- 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, 2026-10-16.
- Patch
- Available – fixed in fb1b50ab699211e777dca5ccfb648788b6a6e519, f742d9c98b5c504fc9e6744eef13a721c2aea486, e165a1d295e7e814e13b0f92c86e5d48309509ce +5
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Aug 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.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: wifi: at76c50x-usb: avoid length underflow in at76_guess_freq() at76_guess_freq() checks only that the received frame is at least a bare 802.11 header (24 bytes) before subtracting the fixed management-body offset: len -= el_off; For both beacon and probe response frames, el_off is 36. If the frame is shorter than el_off, subtracting it causes the calculated IE length to wrap. The length is eventually passed to cfg80211_find_elem_match() as a very large unsigned value, so the element walk runs beyond the RX skb. This path is reached from at76_rx_tasklet() while scanning. If the device delivers a truncated beacon or probe response, the oversized IE length causes an out-of-bounds read during scanning. Skip the IE lookup if the frame does not reach the variable elements, before subtracting el_off.
References
- git.kernel.org/stable/c/cb831aff2f850f72bc5ff5ad77d0a70bb5a84061 (opens in a new tab)
- git.kernel.org/stable/c/4875680d1703f56afa6257ba30244f2fb44ed205 (opens in a new tab)
- git.kernel.org/stable/c/b406f33d234f98c8b310fdab5cbb492d85e98e49 (opens in a new tab)
- git.kernel.org/stable/c/e165a1d295e7e814e13b0f92c86e5d48309509ce (opens in a new tab)
- git.kernel.org/stable/c/bcde7249d45f52f994a9872bedf45994472ade77 (opens in a new tab)
- git.kernel.org/stable/c/fb1b50ab699211e777dca5ccfb648788b6a6e519 (opens in a new tab)
- git.kernel.org/stable/c/f742d9c98b5c504fc9e6744eef13a721c2aea486 (opens in a new tab)
- git.kernel.org/stable/c/61a799ffd1e5a4fd3702d547828b7ff3d161468e (opens in a new tab)