CVE-2026-121603
Solanum before commit 2ea1382 Buffer Overflow via Server-to-Server KILL Handler
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.5
Solanum before commit 2ea1382 Buffer Overflow via Server-to-Server KILL Handler
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
- Record
CVE-2026-121603- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-120
- Updated
- 2026-11-03
EUVDEUVD-2026-116038
8.5
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
- Record
EUVD-2026-116038- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-6cq2-4j8w-7hvj
8.5
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows...
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
- Record
GHSA-6cq2-4j8w-7hvj- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/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
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-120
- Updated
- 2026-11-03
NVD
8.5
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
- Record
CVE-2026-121603- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/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
- 6.5 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N - Weakness
- CWE-120
- Updated
- 2026-11-03
OSV
8.5
Solanum before commit 2ea1382 Buffer Overflow via Server-to-Server KILL Handler
Solanum before commit 2ea1382 contains a buffer overflow vulnerability in ms_kill() that allows malicious linked servers to corrupt memory by sending an overlong kill reason. Attackers controlling a rogue or compromised peer server can send a reason exceeding KILLLEN that overflows a static 512-byte buffer, crashing the ircd or potentially achieving remote code execution.
- Record
CVE-2026-121603- CVSS 4.0
- 8.5 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-120
- Updated
- 2026-11-05
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| references | OSV | |
| published | EUVD | |
| published | EUVD, NVD | |
| aliases, references | CVE List, EUVD, GitHub Advisories | |
| cwes, references, severity, title | CVE List | |
| first indexed | EUVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-121603 is a high vulnerability (CVSS 8.5) in Solanum-ircd Solanum, published November 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.76%, the 55th percentile. No source names a fixed version.
References
github.com/solanum-ircd/solanum/pull/550
github.com/solanum-ircd/solanum/commit/2ea1382e4262b212a91034258c466f0f6754cd61
github.com/solanum-ircd/solanum/blob/7bc7e34c04711247b932666e19ae900cba884540/modules/core/m_kill.c
github.com/solanum-ircd/solanum
vulncheck.com/advisories/solanum-before-commit-2ea1382-buffer-overflow-via-server-to-server-kill-handler
nvd.nist.gov/vuln/detail/CVE-2026-121603
github.com/advisories/GHSA-6cq2-4j8w-7hvj
github.com/CVEProject/cvelistV5/tree/main/cves/2026/121xxx/CVE-2026-121603.json