01 Record
CVE-2026-19735
Predictable TCP initial sequence numbers when the RFC 6528 secret key generation fails silently in the Zephyr TCP stack
MediumPUBLISHEDCNA: zephyr
CNA base score4.8 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
02 Description
Predictable TCP initial sequence numbers when the RFC 6528 secret key generation fails silently in the Zephyr TCP stack
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- Not scored by EPSS
- EPSS percentile
- Not scored by EPSS
- NVD base score
- 4.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- NVD analysis status
- Received. NVD last modified this record on 2026-10-11.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-10-11 17:14Z4 HR AGO
- Last updated
- 2026-10-11 17:14Z4 HR AGO
- Reserved
- 2026-08-13
- Assigning CNA
- zephyr
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- Weaknesses
- CWE-330Use of Insufficiently Random ValuesClass
- Data version
- 5.2
- Document digest
- 586150fd93682ae55e17b361b187ea84291f154129dbfda6ab9461970cfbded3
05 Affected products
VendorProductVersionsPlatforms
06 References
- github.comFix commithttps://github.com/zephyrproject-rtos/zephyr/commit/700888e3ecff8474f4fe7dfa8782b8869053222b
- github.comGHSA-37mc-2q9v-fp64https://github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-37mc-2q9v-fp64