CVE-2026-15340
Savannah lwIP SMTP client Classic Buffer Overflow
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Savannah lwIP SMTP client Classic Buffer Overflow
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
- Record
CVE-2026-15340- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
EUVDEUVD-2026-95820
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
- Record
EUVD-2026-95820- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-5x4f-h328-9vjh
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
- Record
GHSA-5x4f-h328-9vjh- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
NVD
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
- Record
CVE-2026-15340- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 9.8 Critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-120
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-15340
lwIP SMTP client does not check the size of inputs, potentially allowing a buffer overflow.
- Record
DEBIAN-CVE-2026-15340- CVSS 4.0
- 9.3 Critical
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
lwipDebian:12 |
All versions, plus listed versions 2.1.3+dfsg1-22.1.3+dfsg1-32.1.3+dfsg1-42.2.0+dfsg1-12.2.0+dfsg1-2 Show 17 moreShow less2.2.0+dfsg1-32.2.0+dfsg1-42.2.0+dfsg1-52.2.0+dfsg1-62.2.0+dfsg1-6.12.2.0+dfsg1-6.1~exp12.2.0+dfsg1-72.2.0+dfsg1-82.2.0+dfsg1-92.2.1+dfsg1-12.2.1+dfsg1-22.2.1+dfsg1-32.2.1+dfsg1-42.2.1+dfsg1-52.2.1+dfsg1-62.2.1+dfsg1-72.2.1+dfsg1-8 |
None known |
lwipDebian:13 |
All versions, plus listed versions 2.2.1+dfsg1-12.2.1+dfsg1-1+deb13u12.2.1+dfsg1-22.2.1+dfsg1-32.2.1+dfsg1-4 Show 4 moreShow less2.2.1+dfsg1-52.2.1+dfsg1-62.2.1+dfsg1-72.2.1+dfsg1-8 |
None known |
lwipDebian:14 |
All versions, plus listed versions 2.2.1+dfsg1-12.2.1+dfsg1-22.2.1+dfsg1-32.2.1+dfsg1-42.2.1+dfsg1-52.2.1+dfsg1-62.2.1+dfsg1-72.2.1+dfsg1-8 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-15340 is a critical vulnerability (CVSS 9.3) in Savannah Lwip Smtp Client, published October 9, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.37%, the 30th percentile. No source names a fixed version.