CVE-2026-109125: unbound security update
Affects unboundSource GCVE Database
Mentioned vulnerabilities
Not known to be exploited · CVSS 5.3 Medium : upgrade to 1.17.1-25.oe2403sp3 when convenient.
Data as of 4 Nov 2026, 16:47 UTC
Thin evidence
One scorer or none| CNA (NLnet Labs) | CVSS 3.1 | 5.3 |
|---|
- Patch
- Available – fixed in 1.17.1-25.oe2403sp3
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 4 Nov 2026.
What to do
Upgrade unbound to 1.17.1-25.oe2403sp3.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
openEuler 24.03-LTS-SP3unboundpkg:rpm/openEuler/unbound&distro=openEuler-24.03-LTS-SP3Other threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available in Unbound version 1.17.1-25.oe2403sp3 that addresses these vulnerabilities. Users should upgrade to this fixed version to mitigate the described issues. Since the cache side-channel attack requires non-default configuration, reviewing and avoiding 'unwanted-reply-threshold' settings greater than zero can reduce risk until patched. No other specific mitigations are indicated by the vendor advisory.
Description
NLnet Labs Unbound up to and including version 1.26.1 contains multiple vulnerabilities including a cache-level side-channel that can be exploited under specific non-default configurations, DNSSEC validation bypasses in certain trust-anchor configurations, and a denial-of-service condition via excessive compression pointer traversal. These issues can lead to cache poisoning, incorrect DNSSEC validation resulting in insecure treatment of zones, and performance degradation. A fix is available in version 1.17.1-25.oe2403sp3.
References
- openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4734 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-109125 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-35501 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-50106 (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-96405 (opens in a new tab)