Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-33278— Possible arbitrary code execution during DNSSEC validation

AI Predicted 9.8 Difficulty: Moderate EPSS 1.27% · P66

Possible ATT&CK Techniques 1AI

T1190 · Exploit Public-Facing Application

Affected Version Matrix 1

VendorProductVersion RangeStatus
NLnet LabsUnbound1.19.1< 1.25.1affected
Get alerts for future matching vulnerabilitiesLog in to subscribe

I. Basic Information for CVE-2026-33278

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Possible arbitrary code execution during DNSSEC validation
Source: NVD (National Vulnerability Database)
Vulnerability Description
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.
Source: NVD (National Vulnerability Database)
CVSS Information
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Type
释放后使用
Source: NVD (National Vulnerability Database)
Vulnerability Title
NLnet Labs Unbound 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
NLnet Labs Unbound是NLnet Labs开源的一个高性能DNS解析器。 NLnet Labs Unbound 1.19.1版本至1.25.0版本存在资源管理错误漏洞，该漏洞源于DNSSEC验证器中深度复制数据结构时错误覆盖目标指针，可能导致拒绝服务和可能的远程代码执行。攻击者可通过控制恶意签名区域并查询易受攻击的Unbound利用此漏洞。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

VendorProductAffected VersionsCPESubscribe
NLnet LabsUnbound 1.19.1 ~ 1.25.1 -

II. Public POCs for CVE-2026-33278

#POC DescriptionSource LinkShenlong Link
AI-Generated POCPremium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-33278

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-33278 (1)

Same Patch Batch · NLnet Labs · 2026-05-20 · 11 CVEs total

CVE-2026-41292Long list of incoming EDNS options degrades performance
CVE-2026-42959Crash during DNSSEC validation of malicious content
CVE-2026-42923Degradation of service with unbounded NSEC3 hash calculations
CVE-2026-42944Heap overflow with multiple NSID, COOKIE, PADDING EDNS options
CVE-2026-42960Possible cache poisoning via promiscuous records for the authority section
CVE-2026-42534Jostle logic bypass degrades resolution performance
CVE-2026-32792Packet of death with DNSCrypt
CVE-2026-40622Another 'ghost domain names' attack variant
CVE-2026-44390Unbounded name compression in certain cases causes degradation of service
CVE-2026-44608Use after free and crash under special conditions in RPZ code

IV. Related Vulnerabilities

Same product: Unbound
Same vendor: NLnet Labs
Same weakness: CWE-416

V. Comments for CVE-2026-33278

No comments yet

Leave a comment