NLnet Labs NSD up to 4.14.2 APL buffer overflow

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.2$0-$5k1.84-

Summaryinfo

A vulnerability identified as critical has been detected in NLnet Labs NSD up to 4.14.2. The impacted element is an unknown function of the component APL Handler. Performing a manipulation results in buffer overflow. This vulnerability is cataloged as CVE-2026-12246. It is possible to initiate the attack remotely. There is no exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in NLnet Labs NSD up to 4.14.2. This affects some unknown functionality of the component APL Handler. The manipulation with an unknown input leads to a buffer overflow vulnerability. CWE is classifying the issue as CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. This is going to have an impact on integrity, and availability. The summary by CVE is:

NSD version 4.14.0 introduced a bug where a specially crafted APL RR, with an adflength larger than permitted for the address family will overwrite the stack when the zone is written to disk, with a maximum of 111 attacker controlled bytes.

The weakness was shared by Qifan Zhang (zhangph). The advisory is shared at nlnetlabs.nl. This vulnerability is uniquely identified as CVE-2026-12246 since 06/15/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. Neither technical details nor an exploit are publicly available.

Upgrading to version 4.14.3 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-39184). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 5.4
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.4
VulDB Temp Score: 5.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NSD 4.14.3

Timelineinfo

06/15/2026 CVE reserved
06/25/2026 +10 days Advisory disclosed
06/25/2026 +0 days VulDB entry created
06/25/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: nlnetlabs.nl
Researcher: Qifan Zhang (zhangph)
Status: Confirmed

CVE: CVE-2026-12246 (🔒)
GCVE (CVE): GCVE-0-2026-12246
GCVE (VulDB): GCVE-100-373809
EUVD: 🔒

Entryinfo

Created: 06/25/2026 12:28
Updated: 06/25/2026 16:23
Changes: 06/25/2026 12:28 (70), 06/25/2026 16:23 (1)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Might our Artificial Intelligence support you?

Check our Alexa App!