Is there a patch available for CVE-2026-98255?

Yes, a patch is available for CVE-2026-98255. Update the affected software to the latest version immediately.

Linux CVE-2026-98255

EUVD-2026-93183

2026-10-06 Linux

GHSA-vm2w-hjrq-h79w

Information Disclosure Linux

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Monitor Track and reassess. Why: No CVSS yet + weak signal (CWE or non-zero EPSS).

Patch available 0.2% exploitation probability (EPSS)

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AnalysisCVE.org

In the Linux kernel, the following vulnerability has been resolved:

tcp: exclude old ACKs from tcp fast path

Exclude old ACKs before SND.UNA from the tcp fast path as well as ACKs after SND.NXT.

Such ACKs will fall through to the slow path, where tcp_ack() performs the appropriate validation and challenge ACK handling according to RFC5961 and Commit 3d501dd326fb1c7 ("tcp: do not accept ACK of bytes we never sent").

This prevents old ACKs from being accepted or modifying connection state as part of the fast path before appropriate ACK validation is applied. In particular, this prevents payload carried by a segment with an excessively old ACK from advancing RCV.NXT before the ACK is rejected.

Affected VersionsENISA

Linux patch: 5.10.271

Linux patch: 6.18.54

Linux patch: 5.15.222

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <b86e1e5a4bbcbbccde8b7a3d3486604b581f6628

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <ff037920c688ae6ca1153fec01e90e6782712455

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <8205ac5ddb42a1843fa8d6a8c295b5c7f4f8c6ed

Linux patch: 6.6.158

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <f81e6c3fb06327bc49cdd6e559845293ba06a704

Linux patch: 7.2.8

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <1c8448db5cf35a13d82b0c9004ffdb49358883e7

Linux patch: 6.1.189

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <6eb9b697f50b73b9684e466c1e97f4ca8e947a59

Linux patch: 7.3-rc4

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <07cacab90290f795bad2e566790f4ba8e84cdf5f

Linux patch: 0

Linux 31770e34e43d6c8dee129bfee77e56c34e61f0e5 <8309dc2cc360056aa9cd2acfbfc25930798c3b66

Linux 4.14

Linux patch: 6.12.112

Affected Packages

euvd linux no fix

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

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Exploit and PoC references, threat intelligence from 22 sources

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Lifecycle Timeline

Patch available

Oct 06, 2026 - 10:02 EUVD

CVE Published

Oct 06, 2026 - 08:45 cve.org

UNKNOWN (no severity yet)

Threat Intelligence Overview

EPSS Score

0.2%

Top 93% exploitable

Threat Intel

1 sources

Data Quality

3 sources

Confidence: Low

EUVD

CVE.org

EPSS NEWS MSRC

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity Not scored yet

CISA KEV No

Public POC No

EPSS 0.2%

Patch available Yes

Active threat No

Deciding rule

No CVSS yet + weak signal (CWE or non-zero EPSS)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

Attack Technique

Information Disclosure MEDIUM

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.