CVE-2026-52915: linux Improper Validation of Array Index
Vulnerability summary
CVE-2026-52915 is a high (CVSS 7.1) Improper Validation of Array Index vulnerability in linux. EPSS estimates a 0.13% chance of exploitation in the next 30 days, higher than 2% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 48 · Related 48Timeline
- 24-06-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: ip6t_hbh: reject oversized option lists struct ip6t_opts stores at most IP6T_OPTS_OPTSNR option descriptors, but hbh_mt6_check() does not reject larger optsnr values supplied from userspace. Validate optsnr in the rule setup path so only match data that fits the fixed-size opts array can be installed. This follows the existing xtables pattern of rejecting invalid user-provided counts in checkentry() and keeps the packet matching path unchanged. `struct ip6t_opts` has a fixed `opts[IP6T_OPTS_OPTSNR]` array, where `IP6T_OPTS_OPTSNR` is 16, then off-by-one array access is possible: [ 137.924693][ T8692] UBSAN: array-index-out-of-bounds in ../net/ipv6/netfilter/ip6t_hbh.c:110:29 [ 137.926167][ T8692] index 16 is out of range for type '__u16 [16]'
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- NVDNIST7.1HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
EPSS trend
Probability
0.13%
Chance of exploitation in the next 30 days
Percentile
2%
Versus all other CVEs
30-day change
0.00 pp
From 0.13% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-129Improper Validation of Array IndexThe product uses untrusted input when calculating or using an array index, but the product does not validate or incorrectly validates the index to ensure the index references a valid position within the array.
- CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.
Affected systems
Ubuntu167 products
- linuxAll versions (No fix recorded) | < 5.15.0-186.196 | < 6.8.0-139.139 | < 7.0.0-28.28
- linux-allwinner-5.19All versions (No fix recorded)
- linux-awsAll versions (No fix recorded) | < 5.15.0-1112.119 | < 6.8.0-1064.67 | < 7.0.0-1009.9
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 2d523ba48d4ecc46acfb6aba548292cfcce1ac02 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 588933f1a2ca5ff99274f8c9f25dc3a25d0191c3 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 784aadea7a108c9f90985683caa87fb0198c6a39 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 41ec2e242f1702e8370ddfe14d22b7a766021c3e | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < db0250470f023f159094052c0bd5ab026a88ae93 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 57b0ac5e1b46f1f0338dff392ef2092e2871b412 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6feb43c0995ab3a9c826707eb46541a1696fe4f7 | ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 4322dcde6b4173c2d8e8e6118ed290794263bcc8 | 2.6.12
- linux_kernel≥ 2.6.12.1, < 5.10.258 | ≥ 5.11, < 5.15.209 | ≥ 5.16, < 6.1.175 | ≥ 6.2, < 6.6.142 | ≥ 6.7, < 6.12.92 | ≥ 6.13, < 6.18.34 | ≥ 6.19, < 7.0.11 | 2.6.12 | 2.6.12:rc2 | 2.6.12:rc3 | 2.6.12:rc4 | 2.6.12:rc5 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3 | 7.1:rc4
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
3 vendors · 170 products
