CVE-2026-103415 Memory corruption in NetX Duo
A malicious server can trigger a buffer overflow in Eclipse NetX Duo TLS clients during HelloRetryRequest processing, potentially leading to code execution or crashes.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-103415?
CVE-2026-103415 is a critical memory corruption vulnerability in Eclipse Foundation NetX Duo, published on 14 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-787
Which versions are affected by CVE-2026-103415?
How do I fix CVE-2026-103415?
No fix has been published for CVE-2026-103415 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-103415 being exploited?
There is no known exploitation of CVE-2026-103415 in the wild and no public exploit code.
Sources
Also known as GHSA-5pv3-rhf5-gwgq.