CVE-2026-23247: tcp: secure_seq: add back ports to TS offset

mediumCVSS 6.5CVE-2026-23247

CSIRTS triage

Other

What: Linux kernel TCP secure_seq function missing port inclusion in timestamp offset calculation.
Who is affected: Systems running affected Linux kernel versions are exposed.
Urgency: Medium urgency; CVSS 6.5 indicates moderate impact to TCP security properties.
Action: Update to a patched Linux kernel version addressing CVE-2026-23247.

AI-assisted analysis generated from the source advisory — verify against the original.

Details

Source: Microsoft Security Response Center (INTL · vendor-psirt · site)
Severity: medium — CVSS 6.5
Published: 2026-08-06
Exploitation: Not in CISA KEV at last sync

Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-23247

Exploitation outlook

EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.

Low exploitation riskCVE-2026-232470.12% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 2% of all EPSS-scored CVEs.

Referenced CVEs

CVE	CSIRTS overview	External
CVE-2026-23247	coverage & exploitation status	NVD · CVE.org

Same CVEs, other sources

How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.

high[UPDATE] [high] Linux Kernel: Multiple vulnerabilitiescert-bund
unknownDebian Linux Kernel Multiple Vulnerabilitieshkcert
unknownMultiple vulnerabilities in the Debian Linux kernel (June 26, 2026)cert-fr-avis
unknownDSA-6355-1 linux - security updatedebian

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