Vulnerability-Lookup

GHSA-CH73-G8QV-R6R5

Vulnerability from github – Published: 2026-08-10 21:32 – Updated: 2026-08-10 21:32

Details

When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user's home directory. The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username e.g. thousands of characters, forces the thread to exhaust its stack space. Thus if an application passes untrusted, attacker-controlled input to the wordexp function, an attacker can trigger a stack clash.

Severity

6.6 (Medium)


                  
                    CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:L/SA:H/E:U

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  "affected": [],
  "aliases": [
    "CVE-2026-6791"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-121"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T19:17:30Z",
    "severity": "MODERATE"
  },
  "details": "When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user\u0027s home directory.  The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username e.g. thousands of characters, forces the thread to exhaust its stack space. Thus if an application passes untrusted, attacker-controlled input to the wordexp function, an attacker can trigger a stack clash.",
  "id": "GHSA-ch73-g8qv-r6r5",
  "modified": "2026-08-10T21:32:03Z",
  "published": "2026-08-10T21:32:03Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-6791"
    },
    {
      "type": "WEB",
      "url": "https://sourceware.org/bugzilla/show_bug.cgi?id=34091"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:L/SA:H/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-6791 (GCVE-0-2026-6791)

Vulnerability from cvelistv5 – Published: 2026-08-10 18:41 – Updated: 2026-08-12 18:01

Title

Potential stack-based buffer clash during tilde expansion in wordexp

Summary

Severity

6.6 (Medium)


                        
                          CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:L/SA:H/E:U

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-12 18:01 UTC

CWE

CWE-121 - Stack-based buffer overflow

Assigner

glibc

References

1 reference

URL	Tags
https://sourceware.org/bugzilla/show_bug.cgi?id=34091	issue-tracking

Impacted products

1 product

Vendor	Product	Version
The GNU C Library	glibc	Affected: 2.0 , ≤ 2.43 (custom)

Credits

storm / 고준용 <rhwnsdyd1112@gmail.com>

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                "id": "CVE-2026-6791",
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                "timestamp": "2026-08-12T18:01:21.626992Z",
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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-CH73-G8QV-R6R5

CVE-2026-6791 (GCVE-0-2026-6791)

Tags

Sightings

Nomenclature