Signal is active with 2 mentions in latest observed window
Recommended action window: Monitor and triage in normal cycle
NVD description
Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Attacker can force managesieve-login to be unavailable by repeatedly crashing the process. Protect access to managesieve protocol, or install fixed version. No publicly available exploits are known.
Priority
LOW
Exploitation
NONE
PoC
NONE
Patch
AVAILABLE
Momentum
NONE
If you run products in this scope, you should treat this CVE as relevant to your environment.
CVE-2026-27858 Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory. Attacker can force managesieve-lo… https://www.cve.org/CVERecord?id=CVE-2026-27858
Post summary
The post announces CVE‑2026‑27858, detailing a memory‑allocation bug in managesieve that can be triggered before authentication.
🚨 Cyber Alert! CVE-2026-27858 could lead to DoS in managesieve due to excessive memory allocation before authentication. Protect your email servers by limiting access and patching ASAP! Explore prevention strategies here 👉 https://www.tenable.com/cve/CVE-2026-27858 #CyberSecurity #CVE #DoS
Post summary
CVE‑2026‑27858 is a denial‑of‑service flaw in managesieve that can be mitigated by patching and limiting access; no active exploitation or PoC was reported.
2 of 2 entries
| Part | Vendor | Product | Version | Target SW | Target HW |
|---|---|---|---|---|---|
| App | dovecot | dovecot | - | - | - |
| App | open-xchange | dovecot | - | - | - |