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NVD / CVE Program· CNA Linux

CVE-2026-68373: wifi: at76c50x-usb: avoid length underflow in at76_guess_freq()

HighCVSS 8.1 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 32/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.27% (FIRST EPSS).
  • Someone on the same network segment can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 4875680d1703f56afa6257ba30244f2fb44ed205, 61a799ffd1e5a4fd3702d547828b7ff3d161468e, b406f33d234f98c8b310fdab5cbb492d85e98e49; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 4875680d1703f56afa6257ba30244f2fb44ed205, 61a799ffd1e5a4fd3702d547828b7ff3d161468e, b406f33d234f98c8b310fdab5cbb492d85e98e49; azl3 kernel 6.6.143.1-1 on Azure Linux 3.0 6.6.150.1-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

Published
Aug 10, 2026
Updated
Oct 19, 2026
EPSS
0.2% · 20th percentile

Report tools

JSON

Action score

32

Monitor

Low priority for now.

CVSS
32 / 40 · 8.1 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · Linux
8.1
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-68373

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  • when exploit code appears or is weaponized
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  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 2.6.30affected
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before cb831aff2f850f72bc5ff5ad77d0a70bb5a84061affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before 4875680d1703f56afa6257ba30244f2fb44ed205affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before b406f33d234f98c8b310fdab5cbb492d85e98e49affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before e165a1d295e7e814e13b0f92c86e5d48309509ceaffected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before bcde7249d45f52f994a9872bedf45994472ade77affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before fb1b50ab699211e777dca5ccfb648788b6a6e519affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before f742d9c98b5c504fc9e6744eef13a721c2aea486affected · git
    • 1264b951463a00efebe1bb596499aaad620ec8af and later · before 61a799ffd1e5a4fd3702d547828b7ff3d161468eaffected · git
    • before 2.6.30not affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.101-1~deb12u16.12.101-1~deb12u1
Debian:13linuxbefore 6.12.101-16.12.101-1
Debian:14linuxbefore 7.1.6-17.1.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-68367Aug 10, 2026 · usb: gadget: f_tcm: synchronize delayed set_alt with teardown
    0Monitor
  • ← EarlierCVE-2026-68368Aug 10, 2026 · usb: gadget: f_ncm: validate datagram bounds in ncm_unwrap_ntb()
    0Monitor
  • Later →CVE-2026-68374Aug 10, 2026 · usb: core: sysfs: add lock to bos_descriptors_read()
    31Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux4875680d1703f56afa6257ba30244f2fb44ed205Vendor (CNA)
Linux Linux61a799ffd1e5a4fd3702d547828b7ff3d161468eVendor (CNA)
Linux Linuxb406f33d234f98c8b310fdab5cbb492d85e98e49Vendor (CNA)
Linux Linuxbcde7249d45f52f994a9872bedf45994472ade77Vendor (CNA)
Linux Linuxcb831aff2f850f72bc5ff5ad77d0a70bb5a84061Vendor (CNA)
Linux Linuxe165a1d295e7e814e13b0f92c86e5d48309509ceVendor (CNA)
Linux Linuxf742d9c98b5c504fc9e6744eef13a721c2aea486Vendor (CNA)
Linux Linuxfb1b50ab699211e777dca5ccfb648788b6a6e519Vendor (CNA)
azl3 kernel 6.6.143.1-1 on Azure Linux 3.06.6.150.1-1 · CBL-Mariner ReleasesMicrosoft (MSRC)
debian:linux6.1.187-1 · Debian:12Package registry (OSV)
debian:linux-6.126.12.101-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-681580 days apartlibceph: Fix multiplication overflow in decode_new_up_state_weight()
    39Monitor
  • CVE-2026-720145 days apartdrbd: reject data replies with an out-of-range payload size
    39Monitor
  • CVE-2026-6398422 days apartipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress()
    39Monitor
  • CVE-2025-68794209 days apartiomap: adjust read range correctly for non-block-aligned positions
    39Monitor
  • CVE-2026-681080 days apartdrm/amdgpu/vce: fix integer overflow in image size
    35Monitor
  • CVE-2026-681250 days apartmac802154: llsec: reject frames shorter than the authentication tag
    35Monitor

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Not on record for this CVE: patch commit or PR link · researcher credit · public bounty program.

Technical details

Attack conditions

  • Someone on the same network segment can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
none
Availability
high · the service can be disrupted
Attack vector
Adjacent
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
None
Availability impact
High

Weakness class (CWE)

CWE-190 · Integer Overflow or Wraparound

CVSS vector

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

References

Show all references (7 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records