9.3

CVE-2026-103415: eclipse foundation netx duo Out-of-bounds Write

CVSS: 9.3v4.0CriticalAwaiting analysis
Published 14-10-2026Last modified 16-10-2026
Open JSON

Vulnerability summary

CVE-2026-103415 is a critical (CVSS 9.3) Out-of-bounds Write vulnerability in eclipse foundation netx duo. EPSS estimates a 0.28% chance of exploitation in the next 30 days, higher than 19.5% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.3/10
010
Critical · v4.0 (CVE.org)
EPSS score
0.28%
0%100%
Low · Change unavailable
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 14-10-2026
    PublishedVulnerability first disclosed.
  2. 16-10-2026
    Last modifiedVulnerability information updated.

Description

When a TLS 1.3 client processes a HelloRetryRequest, it copies the server's cookie into its second ClientHello without checking that the cookie fits in the outgoing packet. Both the length and the contents of that cookie come from the peer, and the write happens before certificate authentication completes, so a malicious or compromised server can overwrite memory past the caller supplied TLS packet buffer without presenting a certificate. Only the client path is affected.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.28%

Chance of exploitation in the next 30 days

Percentile

20%

Versus all other CVEs

30-day change

Change unavailable

Change unavailable

15-10-202618-10-2026
EPSS score
0.28%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Eclipse foundation1 product

1 vendor · 1 product

References

2 links