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NVD / CVE Program· CNA Linux

CVE-2026-31780: wifi: wilc1000: fix u8 overflow in SSID scan buffer size calculation

Noroxi assessment

Priority: Monitor (action score 31/100)

  • 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: 0.14% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 0c7f21d8bd2f93998b72b7a7f93152336aeca4dd, 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99, 549f02d8ec94d39092ab6d9b103d0d6783a4b024.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 0c7f21d8bd2f93998b72b7a7f93152336aeca4dd, 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99, 549f02d8ec94d39092ab6d9b103d0d6783a4b024 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: wilc1000: fix u8 overflow in SSID scan buffer size calculation The variable valuesize is declared as u8 but accumulates the total length of all SSIDs to scan. Each SSID contributes up to 33 bytes (IEEE80211_MAX_SSID_LEN + 1), and with WILC_MAX_NUM_PROBED_SSID (10) SSIDs the total can reach 330, which wraps around to 74 when stored in a u8. This causes kmalloc to allocate only 75 bytes while the subsequent memcpy writes up to 331 bytes into the buffer, resulting in a 256-byte heap buffer overflow. Widen valuesize from u8 to u32 to accommodate the full range.

HighCVSS 7.8 · v3.1—No exploit Fix available
Published
May 1, 2026
Updated
Aug 5, 2026
EPSS
0.1% · 3th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CNA vs NVD score

NVD
—
CNA · Linux
7.8
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

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Follow CVE-2026-31780

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • 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.

VendorProduct
linuxlinux kernel

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.2 and later · before 5.10.253
  • linux linux kernel5.11 and later · before 5.15.203
  • linux linux kernel5.16 and later · before 6.1.168
  • linux linux kernel6.2 and later · before 6.6.134
  • linux linux kernel6.7 and later · before 6.12.81
  • linux linux kernel6.13 and later · before 6.18.22
  • linux linux kernel6.19 and later · before 6.19.12
  • linux linux kernel7.0

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

    • 4.2affected
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99affected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before 549f02d8ec94d39092ab6d9b103d0d6783a4b024affected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before bfbddeadd4779651403035ee177ae2f22f9f5521affected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before 9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7affected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before c97b2a00059608592ad0d86fbb813a4f8cf9464baffected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before d8388614de613c28eeb659c10115060a83739924affected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before 0c7f21d8bd2f93998b72b7a7f93152336aeca4ddaffected · git
    • c5c77ba18ea66aa05441c71e38473efb787705a4 and later · before d049e56b1739101d1c4d81deedb269c52a8dbba0affected · git
    • before 4.2not affected · semver

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.170-16.1.170-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.12-16.19.12-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31769May 1, 2026 · gpib: fix use-after-free in IO ioctl handlers
    31Monitor
  • ← EarlierCVE-2026-31770May 1, 2026 · hwmon: (occ) Fix division by zero in occ_show_power_1()
    22Monitor
  • Later →CVE-2026-31782May 1, 2026 · perf/x86: Fix potential bad container_of in intel_pmu_hw_config
    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 Linux0c7f21d8bd2f93998b72b7a7f93152336aeca4ddVendor (CNA)
Linux Linux34a23fd9ddd683a03c7e8cc0ceded3e59e354b99Vendor (CNA)
Linux Linux549f02d8ec94d39092ab6d9b103d0d6783a4b024Vendor (CNA)
Linux Linux9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7Vendor (CNA)
Linux Linuxbfbddeadd4779651403035ee177ae2f22f9f5521Vendor (CNA)
Linux Linuxc97b2a00059608592ad0d86fbb813a4f8cf9464bVendor (CNA)
Linux Linuxd049e56b1739101d1c4d81deedb269c52a8dbba0Vendor (CNA)
Linux Linuxd8388614de613c28eeb659c10115060a83739924Vendor (CNA)
debian:linux6.1.170-1 · 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.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

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

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

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

All national notices →

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

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

Weakness class (CWE)

CWE-787 · Out-of-bounds Write

CVSS vector

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

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (7 more)

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

All records