CVE-2026-89092
Received
Received - Intake
Stack Overflow in GNU C Library nscd Service
Vulnerability report for CVE-2026-89092, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-11
Last updated on: 2026-09-11
Assigner: GNU C Library
Description
Description
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.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| gnu | gnu_c_library | 2.3.4 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-789 | The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. |
