The nscd service in the GNU C Library 2.3.4 onwards may crash due to a stack overflow when a...
Summary
Vulnerability reported (CVE-2026-89092). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
The nscd service in the GNU C Library 2.3.4 onwards may crash due to a
stack overflow when a malicious DNS server returns too large a response
for a DNS query, resulting in degraded DNS resolution for the system.
Exploitation of this bug needs a system that has nscd enabled and using
an untrusted DNS server for name resolution, with the compromised DNS
server being capable of processing records large enough to result in a
stack overflow in an nscd thread stack. During experimentation, bind 9
was unable to handle large records, but that could change in future or
with a different name server. In typical installations, nscd is
executed in an isolated context as its own user without a shell, due to
which any compromise of that service is isolated.
There is a remote possibility of nscd cache corruption if an attacker
manages to get the stack pointer into a desired point in the heap,
potentially resulting in other caches in nscd being overwritten with
corrupt data through the stack overflow, until the buggy code path
eventually results in a crash.
Finally, a crash in nscd may result in performance degradation when
resolving names, but it does not result in a denial of service.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-89092 has been found.
Risk of unauthorized operations or information disclosure. CVSS score: 4.2/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "CVE-2026-89092" on the vendor's site.
CVE-2026-89092 — CWE-789 / CVSS v3 4.2
Attack vector: adjacent-network / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-789) has been reported.
Check the vendor advisory for the affected versions.
Severity: Medium (CVSS 4.2/10). Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで影響コンポーネントを特定する。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- Debian DEBIAN-CVE-2026-89092 glibc
References
- web sourceware.org
- web sourceware.org
- web openwall.com
- web nvd.nist.gov
- web github.com