CVE-2026-31780: linux Out-of-bounds Write
Vulnerability summary
CVE-2026-31780 is a high (CVSS 7.8) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 8.2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 42 · Related 39Timeline
- 01-05-2026PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- NVDNIST7.8HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
+0.05 pp
From 0.14% on 21-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu157 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-136.136
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1061.64
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < 34a23fd9ddd683a03c7e8cc0ceded3e59e354b99 | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < 549f02d8ec94d39092ab6d9b103d0d6783a4b024 | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < bfbddeadd4779651403035ee177ae2f22f9f5521 | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < 9907ac9b9a18b92fc34b9e4cb9e10f208dc1d3f7 | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < c97b2a00059608592ad0d86fbb813a4f8cf9464b | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < d8388614de613c28eeb659c10115060a83739924 | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < 0c7f21d8bd2f93998b72b7a7f93152336aeca4dd | ≥ c5c77ba18ea66aa05441c71e38473efb787705a4, < d049e56b1739101d1c4d81deedb269c52a8dbba0 | 4.2
- linux_kernel≥ 4.2, < 5.10.253 | ≥ 5.11, < 5.15.203 | ≥ 5.16, < 6.1.168 | ≥ 6.2, < 6.6.134 | ≥ 6.7, < 6.12.81 | ≥ 6.13, < 6.18.22 | ≥ 6.19, < 6.19.12 | 7.0:rc1 | 7.0:rc2 | 7.0:rc3 | 7.0:rc4 | 7.0:rc5 | 7.0:rc6
Debian1 product
- linux< 6.1.170-1 | < 6.12.85-1 | < 6.19.12-1
3 vendors · 160 products
