CVE-2026-43383
CVE-2026-43383 is a critical-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 9.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Critical (CVSS 3.x base score 9.4)
- EPSS exploit prediction: 0% (36th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-28689
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: net/tcp-md5: 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.
Frequently asked questions
- What is CVE-2026-43383?
- In the Linux kernel, the following vulnerability has been resolved: net/tcp-md5: 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.
- How severe is CVE-2026-43383?
- CVE-2026-43383 has a CVSS 3.x base score of 9.4, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity high, and availability high.
- Is CVE-2026-43383 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2026-43383?
- CVE-2026-43383 primarily affects Linux Linux Kernel. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2026-43383?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-43383 have an EU (EUVD) identifier?
- Yes. CVE-2026-43383 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-28689.
- When was CVE-2026-43383 published?
- CVE-2026-43383 was published on 2026-05-08 and last updated on 2026-06-19.
References
- https://git.kernel.org/stable/c/02669e2a4d207068edce7e8b5fafd85822018ce6
- https://git.kernel.org/stable/c/345a9530756528d7ca407663d659c3c40e75c3dd
- https://git.kernel.org/stable/c/46d0d6f50dab706637f4c18a470aac20a21900d3
- https://git.kernel.org/stable/c/5d305a95130a8d08b9545e47f1e18d29d59866cb
- https://git.kernel.org/stable/c/821c8751fdeecdeecabeb11704dd33439c9e4bbc
- https://git.kernel.org/stable/c/ae3831b44f477de048287493e184fc3ff913b624
- https://git.kernel.org/stable/c/b502e97e29d791ff7a8051f29a414535739be218
- https://git.kernel.org/stable/c/ff44ec94d4fc8348600a69de0a8fa1102c23bce8
Affected products (3)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*
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