CVE-2026-101338
Stack overwrite from a specially crafted and formatted SVCB or HTTPS RR
- State
- Published
- Severity
- 8.7 High
- Published
- Oct 14, 2026
- Updated
- Oct 14, 2026
- Reserved
- Sep 28, 2026
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).
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.7 High | 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 | NLnet Labs |
Weaknesses
- CWE-121 Stack-based Buffer Overflow
Affected Products
| Product | Versions |
|---|---|
NSDNLnet Labs |
|
References
- https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-101338.txtvendor-advisory
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