CVE-2026-43384: net/tcp-ao: Fix MAC comparison to be constant-time
Vulnerability summary
CVE-2026-43384 is a critical (CVSS 9.8) vulnerability in linux. EPSS estimates a 0.46% chance of exploitation in the next 30 days, higher than 39.6% of scored vulnerabilities.
Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 0% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 19 · Related 25Timeline
- 08-05-2026PublishedVulnerability first disclosed.
- 05-08-2026Last modifiedVulnerability information updated.
Description
In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.
CVSS metrics
5 scores · 4 sources · 2 versions- 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
0.46%
Chance of exploitation in the next 30 days
Percentile
40%
Versus all other CVEs
30-day change
Decrease -0.21 pp
From 0.67% on 04-10-2026
Known exploited
Compare KEV catalogs
CISA KEVNot in the CISA KEV catalog.
ENISA CNWNot in the ENISA CNW catalog.
CIRCLNot in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeNo weakness data has been published for this record.
Affected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Ubuntu130 products
- linux< 6.8.0-134.134 | < 6.17.0-40.40
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1060.63 | < 6.17.0-1019.19
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 0a3a809089eb1d4a0a2fd0c16b520d603988c859, < 8be6ed64966da48b6c4726918f106c18742a5125 | ≥ 0a3a809089eb1d4a0a2fd0c16b520d603988c859, < a269cbdc442f8658bca35383e34b9d0b0ff95a1c | ≥ 0a3a809089eb1d4a0a2fd0c16b520d603988c859, < 080b0e210088296dd50d6637c06c1db14246adfe | ≥ 0a3a809089eb1d4a0a2fd0c16b520d603988c859, < 67edfec516d30d3e62925c397be4a1e5185802fc | 6.7
- linux_kernel≥ 6.7, < 6.12.78 | ≥ 6.13, < 6.18.19 | ≥ 6.19, < 6.19.9 | 7.0:rc1 | 7.0:rc2
Debian1 product
- linux< 6.12.85-1 | < 6.19.10-1
3 vendors · 133 products
