CVE-2026-82717CNAME synthesis could lead to heap corruption
Updated under an hour ago ()
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It affects NLnet Labs Unbound and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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In NLnet Labs Unbound up to and including 1.26.0, a vulnerability was found in that can progressively corrupt heap memory and under certain systems and compilation options could lead to remote code execution. The vulnerability starts when CNAME synthesis during an upstream response needs to enforce(rewrite) a max TTL value in the packet buffer. Coupled with a compression pointer that points to the overwritten value and invalidates the domain name, it leads to an error path that does not properly move the buffer position and allows for the heap buffer overflow. Since this is heavily reliant on heap memory layout, results are memory corruption that eventually leads to a crash and under specific systems and compilation options remote code execution.
- CVSS
- 8.4 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:U
- Weakness (CWE)
- CWE-122
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- NLnet Labs
- NVD analysis
- Analyzed
- Record last updated
- Sep 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
NLnet Labs Unbound nlnet_labs:unbound (from the name) | before 1.26.1 | CNA record |
nlnetlabs unbound nlnetlabs:unbound | before 1.26.1 | NVD |
References
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-82717.txtvendor-advisory, patch
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.