CVE-2026-101338Stack overwrite from a specially crafted and formatted SVCB or HTTPS RR
Updated under an hour ago ()
Does this affect you?
It affects NLnet Labs NSD. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.32%, higher than 23% of scored CVEs.
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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).
- CVSS
- 8.7 HIGH (v4.0, CNA)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
- Weakness (CWE)
- CWE-121
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.32% (percentile 23)
- Assigned by
- NLnet Labs
- NVD analysis
- Awaiting Analysis
- Record last updated
- Oct 14, 2026
- First seen by InfoSec Signals
- Oct 14, 2026
Affected products
NLnet Labs NSD nlnet_labs:nsd (from the name) | from 4.10.0 before 4.15.3 | CNA record |
References
- https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-101338.txtvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.