CVE-2026-15340 Savannah lwIP SMTP client Classic Buffer Overflow
A buffer overflow in the lwIP SMTP client allows attackers to execute arbitrary code or cause denial of service due to unchecked input sizes.
- 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-2026-15340?
CVE-2026-15340 is a critical memory corruption vulnerability in Savannah lwIP SMTP client, published on 9 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
Weakness: CWE-120
Which versions are affected by CVE-2026-15340?
How do I fix CVE-2026-15340?
No fix has been published for CVE-2026-15340 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-2026-15340 being exploited?
There is no known exploitation of CVE-2026-15340 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-15340, GHSA-5x4f-h328-9vjh.