{"id":"CVE-2026-101338","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-101338","generatedAt":"2026-10-28T01:46:15.526Z","title":"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.","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).","published":"2026-10-14T11:16:57.000Z","lastModified":"2026-10-16T19:56:00.000Z","status":"Awaiting Analysis","sourceIdentifier":"sep@nlnetlabs.nl","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-121"],"affected":[],"epss":{"score":0.0034,"percentile":0.27312,"date":"2026-10-26","history":[{"date":"2026-10-15","score":0.00321,"percentile":0.23444}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-14T11:16:57.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-14T11:16:57.130Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-101338.txt","source":"sep@nlnetlabs.nl"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-101338","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}