CVE-2025-39823: debian debian_linux Improper Validation of Array Index
CVSS: 7.8v3.1HighModified
AliasesUBUNTU-CVE-2025-39823DEBIAN-CVE-2025-39823
Published 16-09-2025Last modified 12-05-2026
Vulnerability summary
CVE-2025-39823 is a high (CVSS 7.8) Improper Validation of Array Index vulnerability in debian debian_linux. EPSS estimates a 0.18% chance of exploitation in the next 30 days, higher than 7.2% of scored vulnerabilities.
CVSS score
7.8/10
010
High · v3.1 (NVD)EPSS score
0.18%
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 44 · Related 40DLA-4327-1DLA-4328-1DSA-6008-1DSA-6009-1OPENSUSE-SU-2025:20081-1SUSE-SU-2025:03600-1SUSE-SU-2025:03601-1SUSE-SU-2025:03613-1SUSE-SU-2025:03615-1SUSE-SU-2025:03626-1SUSE-SU-2025:03628-1SUSE-SU-2025:03633-1SUSE-SU-2025:03634-1SUSE-SU-2025:20851-1SUSE-SU-2025:20861-1SUSE-SU-2025:20870-1SUSE-SU-2025:20898-1SUSE-SU-2025:21074-1SUSE-SU-2025:21139-1SUSE-SU-2025:21179-1SUSE-SU-2025:3716-1SUSE-SU-2025:3725-1SUSE-SU-2025:3751-1SUSE-SU-2025:3761-1SUSE-SU-2026:20560-1USN-7909-1USN-7909-2USN-7909-3USN-7909-4USN-7909-5USN-7910-1USN-7910-2USN-7933-1USN-7938-1USN-8095-1USN-8095-2USN-8095-3USN-8095-4USN-8095-5USN-8100-1USN-8125-1USN-8126-1USN-8165-1USN-8261-1
Timeline
- 16-09-2025PublishedVulnerability first disclosed.
- 12-05-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: x86: use array_index_nospec with indices that come from guest min and dest_id are guest-controlled indices. Using array_index_nospec() after the bounds checks clamps these values to mitigate speculative execution side-channels.
CVSS metrics
4 scores · 3 sources · 2 versionsLow 2.1Preferred score · OSV · Ubuntu (Ecosystem advisory) · calculated from vector
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:L/SI:N/SA:NSourcesSingle source
High 7.8Preferred score · NVD (NIST)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HSourcesAll 3 agree
- 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
0.00 pp
From 0.18% on 20-09-2026
20-09-202620-10-2026
EPSS score0.18%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu144 products
- linuxAll versions (No fix recorded) | < 5.15.0-163.173 | < 6.8.0-106.106
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1097.104 | < 6.8.0-1050.53
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Debian2 products
- linux< 6.1.153-1 | < 6.12.48-1 | < 6.16.5-1
- debian_linuxEOL11.0
Linux2 products
- linux≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < 72777fc31aa7ab2ce00f44bfa3929c6eabbeaf48 | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < 31a0ad2f60cb4816e06218b63e695eb72ce74974 | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < d51e381beed5e2f50f85f49f6c90e023754efa12 | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < 33e974c2d5a82b2f9d9ba0ad9cbaabc1c8e3985f | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < f49161646e03d107ce81a99c6ca5da682fe5fb69 | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < 67a05679621b7f721bdba37a5d18665d3aceb695 | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < f57a4bd8d6cb5af05b8ac1be9098e249034639fb | ≥ 4180bf1b655a791a0a6ef93a2ffffc762722c782, < c87bd4dd43a624109c3cc42d843138378a7f4548 | 4.19
- linux_kernel≥ 4.19, < 5.4.298 | ≥ 5.5, < 5.10.242 | ≥ 5.11, < 5.15.191 | ≥ 5.16, < 6.1.150 | ≥ 6.2, < 6.6.104 | ≥ 6.7, < 6.12.45 | ≥ 6.13, < 6.16.5 | 6.17:rc1 | 6.17:rc2 | 6.17:rc3
3 vendors · 148 products
