CVE-2025-39815: linux
CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2025-39815DEBIAN-CVE-2025-39815
Published 16-09-2025Last modified 05-08-2026
Vulnerability summary
CVE-2025-39815 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.1% of scored vulnerabilities.
CVSS score
7.8/10
010
High · v3.1 (CVE.org)EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 11 · Related 10Timeline
- 16-09-2025PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: RISC-V: KVM: fix stack overrun when loading vlenb The userspace load can put up to 2048 bits into an xlen bit stack buffer. We want only xlen bits, so check the size beforehand.
CVSS metrics
4 scores · 4 sources · 1 versionHigh 7.8Preferred score · CVE.org (CNA)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSources4 sources · 5.5–7.8
- 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 · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
- NVDNIST5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HDiffers
EPSS trend
Probability
0.15%
Chance of exploitation in the next 30 days
Percentile
4%
Versus all other CVEs
30-day change
0.00 pp
From 0.15% on 19-09-2026
19-09-202619-10-2026
EPSS score0.15%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Ubuntu122 products
- linux< 6.8.0-106.106
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1050.53
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 2fa290372dfe7dd248b1c16f943f273a3e674f22, < c76bf8359188a11f8fd790e5bbd6077894a245cc | ≥ 2fa290372dfe7dd248b1c16f943f273a3e674f22, < 6d28659b692a0212f360f8bd8a58712b339f9aac | ≥ 2fa290372dfe7dd248b1c16f943f273a3e674f22, < 799766208f09f95677a9ab111b93872d414fbad7 | 6.8
- linux_kernel≥ 6.8, < 6.12.45 | ≥ 6.13, < 6.16.5 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3
Debian1 product
- linux< 6.12.48-1 | < 6.16.5-1
3 vendors · 125 products
