CyberSecBulletin
CVE-2026-68373NVD status: Received

Linux: Integer Overflow or Wraparound

Published Updated By the CyberSecBulletin desk

CVE-2026-68373 is a high-severity integer overflow or wraparound vulnerability in Linux, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions cb831aff2f850f72bc5ff5ad77d0a70bb5a84061, 4875680d1703f56afa6257ba30244f2fb44ed205, b406f33d234f98c8b310fdab5cbb492d85e98e49 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to cb831aff2f850f72bc5ff5ad77d0a70bb5a84061 or 4875680d1703f56afa6257ba30244f2fb44ed205 or b406f33d234f98c8b310fdab5cbb492d85e98e49 or e165a1d295e7e814e13b0f92c86e5d48309509ce, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, cb831aff2f850f72bc5ff5ad77d0a70bb5a84061; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, 4875680d1703f56afa6257ba30244f2fb44ed205; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, b406f33d234f98c8b310fdab5cbb492d85e98e49; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, e165a1d295e7e814e13b0f92c86e5d48309509ce; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, bcde7249d45f52f994a9872bedf45994472ade77; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, fb1b50ab699211e777dca5ccfb648788b6a6e519; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, f742d9c98b5c504fc9e6744eef13a721c2aea486; 1264b951463a00efebe1bb596499aaad620ec8af up to, but not including, 61a799ffd1e5a4fd3702d547828b7ff3d161468e; and 1 more rangescb831aff2f850f72bc5ff5ad77d0a70bb5a84061, 4875680d1703f56afa6257ba30244f2fb44ed205, b406f33d234f98c8b310fdab5cbb492d85e98e49, e165a1d295e7e814e13b0f92c86e5d48309509ce, bcde7249d45f52f994a9872bedf45994472ade77, fb1b50ab699211e777dca5ccfb648788b6a6e519

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
AdjacentThe attacker must be on the same local network segment.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by CNA.

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Integer Overflow or Wraparound

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How developers prevent this class of flaw

  • Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Use libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).

More Integer Overflow or Wraparound vulnerabilities (CWE-190)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Integer Overflow or Wraparound vulnerabilities

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