Vulnerability-Lookup

GHSA-RM44-GPWR-XH4Q

Vulnerability from github – Published: 2026-11-11 18:31 – Updated: 2026-11-11 18:31

Details

These conversions store each wide input character into the caller's char array as a multibyte sequence. The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte. A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end. The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process. An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination.

The narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the 'a' and 'm' allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon. This issue affects all architectures and ABIs supported by the GNU C Library.

Severity

4.8 (Medium)


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

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-115819"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-193"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-11-11T16:17:24Z",
    "severity": "MODERATE"
  },
  "details": "Calling the wide scanf family of functions (swscanf, fwscanf, wscanf, vswscanf, vfwscanf and vwscanf) with a %s or %[ conversion without the \u0027l\u0027 length modifier in the GNU C Library version 2.2 to version 2.44 writes an extra null byte one past the end of the destination array when the converted multibyte string and its terminating null byte exactly fill that array.\n\nThese conversions store each wide input character into the caller\u0027s char array as a multibyte sequence.  The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte.  A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end.  The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process.  An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination.\n\nThe narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the \u0027a\u0027 and \u0027m\u0027 allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon.  This issue affects all architectures and ABIs supported by the GNU C Library.",
  "id": "GHSA-rm44-gpwr-xh4q",
  "modified": "2026-11-11T18:31:36Z",
  "published": "2026-11-11T18:31:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-115819"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34989"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0027"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-115819 (GCVE-0-2026-115819)

Vulnerability from cvelistv5 – Published: 2026-11-11 15:36 – Updated: 2026-11-11 15:36

Title

One-byte buffer overflow in wide scanf %s and %[ conversions

Summary

Calling the wide scanf family of functions (swscanf, fwscanf, wscanf, vswscanf, vfwscanf and vwscanf) with a %s or %[ conversion without the 'l' length modifier in the GNU C Library version 2.2 to version 2.44 writes an extra null byte one past the end of the destination array when the converted multibyte string and its terminating null byte exactly fill that array. These conversions store each wide input character into the caller's char array as a multibyte sequence. The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte. A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end. The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process. An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination. The narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the 'a' and 'm' allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon. This issue affects all architectures and ABIs supported by the GNU C Library.

Severity

4.8 (Medium)


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

CWE

CWE-193 - Off-by-one Error

Assigner

glibc CNA under the redhat root

CNA scorecard B 79/100 over 16 records in the last 180 days details

References

2 references

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=34989	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: 2.2 , ≤ 2.44 (custom)

Date Public

2026-11-11 05:00

Credits

Russell Miller

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "glibc",
          "vendor": "The GNU C Library",
          "versions": [
            {
              "lessThanOrEqual": "2.44",
              "status": "affected",
              "version": "2.2",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "Russell Miller"
        }
      ],
      "datePublic": "2026-11-11T05:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Calling the wide scanf family of functions (swscanf, fwscanf, wscanf, vswscanf, vfwscanf and vwscanf) with a %s or %[ conversion without the \u0027l\u0027 length modifier in the GNU C Library version 2.2 to version 2.44 writes an extra null byte one past the end of the destination array when the converted multibyte string and its terminating null byte exactly fill that array.\u003cbr\u003e\u003cbr\u003eThese conversions store each wide input character into the caller\u0027s char array as a multibyte sequence.  The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte.  A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end.  The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process.  An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination.\u003cbr\u003e\u003cbr\u003eThe narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the \u0027a\u0027 and \u0027m\u0027 allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon.  This issue affects all architectures and ABIs supported by the GNU C Library."
            }
          ],
          "value": "Calling the wide scanf family of functions (swscanf, fwscanf, wscanf, vswscanf, vfwscanf and vwscanf) with a %s or %[ conversion without the \u0027l\u0027 length modifier in the GNU C Library version 2.2 to version 2.44 writes an extra null byte one past the end of the destination array when the converted multibyte string and its terminating null byte exactly fill that array.\n\nThese conversions store each wide input character into the caller\u0027s char array as a multibyte sequence.  The conversion ends with the sequence that returns to the initial shift state, which also stores the terminating null byte, and the functions then append a second null byte.  A destination sized for the converted string and one terminator, as the C standard requires the caller to provide, is therefore written one byte past its end.  The out-of-bounds byte is always a null byte, which may corrupt adjacent data or crash the process.  An attacker who supplies the input can trigger the overflow with a string whose converted length exactly fills the destination.\n\nThe narrow scanf functions, the %ls and %l[ conversions into a wchar_t array, and the \u0027a\u0027 and \u0027m\u0027 allocation modifiers are not affected, and storing a wide scanf conversion into a narrow char array is uncommon.  This issue affects all architectures and ABIs supported by the GNU C Library."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.8,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-193",
              "description": "CWE-193 Off-by-one Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-11T15:36:38.804Z",
        "orgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
        "shortName": "glibc"
      },
      "references": [
        {
          "tags": [
            "issue-tracking"
          ],
          "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34989"
        },
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=advisories/GLIBC-SA-2026-0027"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "One-byte buffer overflow in wide scanf %s and %[ conversions",
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "3ff69d7a-14f2-4f67-a097-88dee7810d18",
    "assignerShortName": "glibc",
    "cveId": "CVE-2026-115819",
    "datePublished": "2026-11-11T15:36:38.804Z",
    "dateReserved": "2026-10-23T16:39:56.857Z",
    "dateUpdated": "2026-11-11T15:36:38.804Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

Publication & reservation Sightings KEV catalogs Other timestamps

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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.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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