Vulnerability-Lookup

GHSA-3VCJ-MGHM-MW9P

Vulnerability from github – Published: 2026-09-14 18:31 – Updated: 2026-09-14 18:31

Details

Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding.

Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller.

At the time of publication, no network-facing application impact is known.

Severity

7.7 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-19499"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-122"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-14T18:17:45Z",
    "severity": "HIGH"
  },
  "details": "Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding.\n\nExploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller.\n\nAt the time of publication, no network-facing application impact is known.",
  "id": "GHSA-3vcj-mghm-mw9p",
  "modified": "2026-09-14T18:31:22Z",
  "published": "2026-09-14T18:31:22Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19499"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34510"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0017"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-19499 (GCVE-0-2026-19499)

Vulnerability from cvelistv5 – Published: 2026-09-14 17:11 – Updated: 2026-09-14 19:40

Title

Buffer overflow in strfmon and strfmon_l right-justification padding

Summary

Calling strfmon and strfmon_l in the GNU C Library version 2.38 to 2.44 can write past the end of the caller-supplied output buffer when a conversion uses right-justified width padding. Exploitation requires an application code path that calls strfmon or strfmon_l with right-justified width padding into a destination buffer that is large enough for the padding to succeed but too small for the internal memmove call. The field width or format may be attacker-influenced or a fixed susceptible pattern in the caller. At the time of publication, no network-facing application impact is known.

Severity

7.7 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-14 19:40 UTC

CWE

CWE-122 - Heap-based buffer overflow

Assigner

glibc redhat root

References

2 references

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=34510	issue-tracking
https://sourceware.org/git/?p=glibc.git;a=blob_pl…	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
The GNU C Library	glibc	Affected: 2.38 , ≤ 2.44 (custom)

Date Public

2026-08-11 04:00

Credits

AISLE in partnership with Red Hat

Show details on NVD website

JSON

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                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-14T19:40:33.799943Z",
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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GHSA-3VCJ-MGHM-MW9P

CVE-2026-19499 (GCVE-0-2026-19499)

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