CVE-2026-42959highCWE-824

CVE-2026-42959: falha de alta gravidade em NLnet Labs Unbound

Crash during DNSSEC validation of malicious content

Publicada em · Atualizada em

Seguir esta CVE+ Monitorar Unbound+ Monitorar unbound

Aviso por e-mail quando ela entrar no KEV, ganhar PoC pública ou subir de nota.

21Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 8.7epss 0.8%
NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets for ADDITIONAL section rrsets. DNAME duplication could increase the ANSWER section count and authority filtering could decrease the AUTHORITY section count and create an uninitialized array slot. Combining these two, the validator later dereferences this uninitialized pointer, causing an immediate process crash. An adversary controlling a DNSSEC-signed domain can trigger this bug with a single query by configuring a DNAME chain with unsigned CNAMEs and a response containing unsigned AUTHORITY records alongside signed ADDITIONAL glue records. Unbound 1.25.1 contains a patch with a fix to use the proper counters to calculate the write offsets.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/U:Red
Produtos afetados
NLnet Labs · Unbound
CVEs relacionadas — NLnet Labs Unbound

No mesmo produto, das mais perigosas para as menos.

CVE-2024-1931HIGHDenial of service when trimming EDE text on positive repliesEPSS 2.5%CVE-2022-3204HIGHNRDelegation AttackEPSS 1.6%CVE-2026-33278CRITICALPossible arbitrary code execution during DNSSEC validationEPSS 1.4%CVE-2022-30699—Novel "ghost domain names" attack by updating almost expired delegation informationEPSS 1.2%CVE-2022-30698—Novel "ghost domain names" attack by introducing subdomain delegationsEPSS 1.2%CVE-2026-81642CRITICALHeap buffer overflow and possible Remote Code Execution when digesting DNSKEYEPSS 1.0%