Distribution advisory
This page covers CVE-2026-33278 as tracked by Ubuntu, for the package unbound. The fix is available in version 1.24.2-1ubuntu2.1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.
CVSS metrics in full
The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Attack vector: Network — reachable from anywhere that can route to the service.
- Attack complexity: Low — the attack works reliably, with no preparation.
- Privileges required: None — an unauthenticated stranger can try it.
- User interaction: None — nobody has to be tricked into anything.
- Scope: Unchanged — the damage stays inside the vulnerable component.
- Confidentiality impact: High — total loss, or loss the attacker controls.
- Integrity impact: High — total loss, or loss the attacker controls.
- Availability impact: High — total loss, or loss the attacker controls.
Weakness class
UBUNTU-CVE-2026-33278 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.
Affected software
UBUNTU-CVE-2026-33278 is recorded against 1 package.
- unbound (fixed in 1.24.2-1ubuntu2.1)
Timeline and source
Published on 20 May 2026 and last revised on 30 June 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
ubuntu.com (Report)
www.cve.org (Report)
nlnetlabs.nl (Report)
ubuntu.com (Advisory)
Other advisories for this package
unbound has other advisories on record. If you are patching this one, these are worth checking on the same host:
Same weakness in other software
These advisories are the same class of weakness (CWE-416: Use After Free) in other software:
