{"id":"CVE-2026-101338","state":"PUBLISHED","title":"Stack overwrite from a specially crafted and formatted SVCB or HTTPS RR","description":"When a SVCB or HTTPS RR has filled the wire format RDATA up to the brim, another ECH parameter may overwrite the stack, and once beyond the limit, the base64 decoder can write attacker controlled data of unlimited size.  Zone files which are written out by NSD itself, such as for zones for which the NSD instance is secondary, will not be formatted like this. The zone file must be fed to NSD directly, (but it could come, for example, from an operator controlled provisioning system).","publishedAt":"2026-10-14T10:56:28.223Z","updatedAt":"2026-10-14T14:09:20.163Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"NLnet Labs"},"assigner":"NLnet Labs","products":["NLnet Labs NSD"],"affected":[{"vendor":"NLnet Labs","product":"NSD","defaultStatus":"unaffected","versions":[{"version":"4.10.0","status":"affected","lessThan":"4.15.3","versionType":"semver"}]}],"references":["https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-101338.txt"],"weaknesses":["CWE-121"],"ingestedAt":"2026-10-29T20:10:13.529Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/101xxx/CVE-2026-101338.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-101338","state":"PUBLISHED","datePublished":"2026-10-14T10:56:28.223Z","dateUpdated":"2026-10-14T14:09:20.163Z","assignerShortName":"NLnet Labs","assignerOrgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateReserved":"2026-09-28T14:39:03.778Z"},"containers":{"cna":{"title":"Stack overwrite from a specially crafted and formatted SVCB or HTTPS RR","descriptions":[{"lang":"en","value":"When a SVCB or HTTPS RR has filled the wire format RDATA up to the brim, another ECH parameter may overwrite the stack, and once beyond the limit, the base64 decoder can write attacker controlled data of unlimited size.  Zone files which are written out by NSD itself, such as for zones for which the NSD instance is secondary, will not be formatted like this. The zone file must be fed to NSD directly, (but it could come, for example, from an operator controlled provisioning system)."}],"affected":[{"vendor":"NLnet Labs","product":"NSD","defaultStatus":"unaffected","versions":[{"version":"4.10.0","status":"affected","lessThan":"4.15.3","versionType":"semver"}]}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-101338.txt","tags":["vendor-advisory"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"When reading zone files, a specially crafted and format SVCB or HTTPS record cancause an out of bounds stack overwrite which can be exploited for execution of arbitrary commands."}],"cvssV4_0":{"version":"4.0","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-121","lang":"en","description":"CWE-121 Stack-based Buffer Overflow","type":"CWE"}]}],"providerMetadata":{"shortName":"NLnet Labs","orgId":"206fc3a0-e175-490b-9eaa-a5738056c9f6","dateUpdated":"2026-10-14T10:56:28.223Z"},"solutions":[{"lang":"en","value":"This issue is fixed in 4.15.3 and all later versions."}],"credits":[{"lang":"en","type":"finder","value":"Qifan Zhang from Palo Alto Networks"}],"timeline":[{"time":"2026-08-13T08:12:00.000Z","lang":"en","value":"Issue reported by Qifan Zhang"},{"time":"2026-09-27T15:03:00.000Z","lang":"en","value":"NLnet Labs shares patch"},{"time":"2026-09-28T21:21:00.000Z","lang":"en","value":"Qifan Zhang verifies patch"},{"time":"2026-10-14T12:00:00.000Z","lang":"en","value":"Fix released with version 4.15.3"}],"datePublic":"2026-10-14T12:00:00.000Z","x_generator":{"engine":"cvelib 1.8.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-14T14:09:10.026829Z","id":"CVE-2026-101338","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-14T14:09:20.163Z"}}]}}}