CVE-2026-33278

Published: Mag 20, 2026 Last Modified: Mag 20, 2026
ExploitDB:
Other exploit source:
Google Dorks:
CRITICAL 9,1
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: none
Confidentiality: N/A
Integrity: N/A
Availability: N/A

Description

AI Translation Available

NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the vulnerability by controlling a malicious signed zone and querying a vulnerable Unbound. When DS sub-queries need to suspend validation due to NSEC3 computational budget exhaustion (introduced in Unbound 1.19.1), Unbound deep-copies response messages to preserve them across memory region teardown. A struct-assignment bug overwrites the destination's pointer with the source's pointer. After the sub-query region is freed, the resumed validator dereferences this dangling pointer, triggering a crash or potentially enabling arbitrary code execution. Unbound 1.25.1 contains a patch with a fix to preserve the correct pointer when deep copying the data structure.

EPSS (Exploit Prediction Scoring System)

Trend Analysis

EPSS (Exploit Prediction Scoring System)

Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.

EPSS Score
0,0037
Percentile
0,6th
Updated

Single Data Point

Only one EPSS measurement is available for this CVE. Trend analysis requires multiple data points over time.

416

Use After Free

Stable
Abstraction: Variant Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Availability Confidentiality
Potential Impacts:
Modify Memory Dos: Crash, Exit, Or Restart Read Memory Execute Unauthorized Code Or Commands
Applicable Platforms
Languages: Memory-Unsafe, C, C++
Likelihood of Exploit: High
View CWE Details
672

Operation on a Resource after Expiration or Release

Draft
Abstraction: Class Structure: Simple
Common Consequences
Security Scopes Affected:
Integrity Confidentiality Other Availability
Potential Impacts:
Modify Application Data Read Application Data Other Dos: Crash, Exit, Or Restart
Applicable Platforms
Technologies: Mobile
View CWE Details
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-33278.t…
https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-33278.txt