CVE-2026-64046: linux Improper Input Validation
Vulnerability summary
CVE-2026-64046 is a critical (CVSS 9.8) Improper Input Validation vulnerability in linux. EPSS estimates a 0.51% chance of exploitation in the next 30 days, higher than 42.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 39 · Related 39Timeline
- 19-07-2026PublishedVulnerability first disclosed.
- 19-10-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: net: tls: prevent chain-after-chain in plain text SG Sashiko points out that if end = 0 (start != 0) the current code will create a chain link to content type right after the wrap link: This would create a chain where the wrap link points directly to another chain link. The scatterlist API sg_next iterator does not recursively resolve consecutive chain links. meaning this is illegal input to crypto. The wrapping link is unnecessary if end = 0. end is the entry after the last one used so end = 0 means there's nothing pushed after the wrap: end start i v v v [ ]...[ ][ d ][ d ][ d ][ d ][rsv for wrap] Skip the wrapping in this case. TLS 1.3 can use the "wrapping slot" for it's chaining if end = 0. This avoids the chain-after-chain. Move the wrap chaining before marking END and chaining off content type, that feels like more logical ordering to me, but should not matter from functional perspective.
CVSS metrics
4 scores · 4 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.51%
Chance of exploitation in the next 30 days
Percentile
43%
Versus all other CVEs
30-day change
0.00 pp
From 0.51% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu163 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≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < 49a5faaa471ddcd37b6893970c9916eb836e7c31 | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < 91359966e247c0244c66d50bbb8e74aefa4321c3 | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < 410351158dfef2d67fea6603680b3a6013c6ed9d | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < acdc12b71c9aa4be5dcd2c8062753c6d2033e235 | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < 929b1548e63ac72e104c07d8ee8cbbeeba2fa89a | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < af855f4c966afafef74faf8390c7b86568c0d46d | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < b9c015ef1a7bf1e8dc67f21c6381f36deb2c3a36 | ≥ 9aaaa56845a06aeabdd597cbe19492dc01f281ec, < ff26a0e8377dec07e4a7230db7675bed1b9a6d03 | d529d6c9f7e3aaeac13c4948f79799ccb825f29d | ≥ 5.4.14, < 5.5 | 5.5
- linux_kernel≥ 5.4.14, < 5.5 | ≥ 5.5.1, < 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 | 5.5 | 5.5:rc7 | 7.1:rc1 | 7.1:rc2 | 7.1:rc3
Debian1 product
- linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
3 vendors · 166 products
