Vulnerability-Lookup

GHSA-GWQP-9QGW-C5PV

Vulnerability from github – Published: 2026-09-11 03:30 – Updated: 2026-09-11 06:31

Details

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.

Severity

4.2 (Medium)


                  
                    CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

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{
  "affected": [],
  "aliases": [
    "CVE-2026-89092"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-789"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-11T02:18:35Z",
    "severity": "MODERATE"
  },
  "details": "The nscd service in the GNU C Library 2.3.4 onwards may crash due to a \nstack overflow when a malicious DNS server returns too large a response \nfor a DNS query, resulting in degraded DNS resolution for the system.\n\n\n\nExploitation of this bug needs a system that has nscd enabled and using \nan untrusted DNS server for name resolution, with the compromised DNS \nserver being capable of processing records large enough to result in a \nstack overflow in an nscd thread stack.\u00a0 During experimentation, bind 9 \nwas unable to handle large records, but that could change in future or \nwith a different name server.\u00a0 In typical installations, nscd is \nexecuted in an isolated context as its own user without a shell, due to \nwhich any compromise of that service is isolated.\n\n\n\nThere is a remote possibility of nscd cache corruption if an attacker \nmanages to get the stack pointer into a desired point in the heap, \npotentially resulting in other caches in nscd being overwritten with \ncorrupt data through the stack overflow, until the buggy code path \neventually results in a crash.\n\n\n\nFinally, a crash in nscd may result in performance degradation when \nresolving names, but it does not result in a denial of service.",
  "id": "GHSA-gwqp-9qgw-c5pv",
  "modified": "2026-09-11T06:31:12Z",
  "published": "2026-09-11T03:30:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89092"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34624"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0016"
    },
    {
      "type": "WEB",
      "url": "http://www.openwall.com/lists/oss-security/2026/09/11/2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-89092 (GCVE-0-2026-89092)

Vulnerability from cvelistv5 – Published: 2026-09-11 01:23 – Updated: 2026-09-11 17:02

Title

Stack overflow in nscd due to unbounded alloca use

Summary

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.

Severity

4.2 (Medium)


                        
                          CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-11 16:57 UTC

CWE

CWE-789 - Memory allocation with excessive size value

Assigner

glibc redhat root

References

3 references

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=34624	issue-tracking
https://sourceware.org/git/?p=glibc.git;a=blob_pl…	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/09/11/2

Impacted products

1 product

Vendor	Product	Version
The GNU C Library	glibc	Affected: 2.3.4 , < 2.45 (custom)

Credits

Anmol Singh Rajput

Show details on NVD website

JSON

To clipboard

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          "dateUpdated": "2026-09-11T03:09:09.108Z",
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                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-11T16:57:22.665457Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.

Action not permitted

GHSA-GWQP-9QGW-C5PV

CVE-2026-89092 (GCVE-0-2026-89092)

Tags

Sightings

Nomenclature