CVE-2021-33586

MEDIUM 4.3CVE-2021-33586 · Published 27/05/2021 · updated 17/06/2026

In short

CVE-2021-33586 is a MEDIUM (CVSS 4.3) vulnerability affecting inspircd (inspircd).
Chance of exploitation in the next 30 days (EPSS): 0.89%, higher than 59.4% of all vulnerabilities.
Fix: update to 3.10.0 or later.

Package	Affected versions	Patched versions
inspircd inspircd	`≥ 3.8.0, < 3.10.0`	`3.10.0`

Description

InspIRCd 3.8.0 through 3.9.x before 3.10.0 allows any user (able to connect to the server) to access recently deallocated memory, aka the "malformed PONG" issue.

References

docs.inspircd.org/security/2021-01 · Patch
inspircd/inspircd commit 4350a11 · Patch
security.gentoo.org/glsa/202107-22 · Third Party Advisory

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Package

Affected versions

Patched versions

inspircd

≥ 3.8.0, < 3.10.0

3.10.0

More vulnerabilities in inspircd

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