CVE-2026-31720: linux Out-of-bounds Write
Vulnerability summary
CVE-2026-31720 is a high (CVSS 7.8) Out-of-bounds Write vulnerability in linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 6.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 42 · Related 39Timeline
- 01-05-2026PublishedVulnerability first disclosed.
- 11-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_uac1_legacy: validate control request size f_audio_complete() copies req->length bytes into a 4-byte stack variable: u32 data = 0; memcpy(&data, req->buf, req->length); req->length is derived from the host-controlled USB request path, which can lead to a stack out-of-bounds write. Validate req->actual against the expected payload size for the supported control selectors and decode only the expected amount of data. This avoids copying a host-influenced length into a fixed-size stack object.
CVSS metrics
4 scores · 3 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
EPSS trend
Probability
0.18%
Chance of exploitation in the next 30 days
Percentile
7%
Versus all other CVEs
30-day change
+0.05 pp
From 0.13% 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≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 557d1d4e862eccd0b74cc377b66de3e1e8d49605 | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 21b11e8581285c6f10ef43d05df349d445f24273 | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 0d41772d98dcaf6c17e875b7d0ea0154ae1191ee | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < c6da4fed7537aec19880c24f6c3a95065adb1406 | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < be2d32f0c3fe333d14c0a9ca90328dacbc3e06b8 | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 8e5eb1d6e6a3d7bbea9c92132d0cda5793176426 | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 26304d124e7f0383f8fe1168b5801a0ac7e16b1c | ≥ c6994e6f067cf0fc4c6cca3d164018b1150916f8, < 6e0e34d85cd46ceb37d16054e97a373a32770f6c | 2.6.31
- linux_kernel≥ 2.6.31, < 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
