Vulnerability-Lookup

CVE-2026-66486 (GCVE-0-2026-66486)

Vulnerability from cvelistv5 – Published: 2026-08-10 10:25 – Updated: 2026-08-10 10:35 X_Open Source

Title

Improper Output Encoding in GNU cpio

Summary

GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed. This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30

Severity

4.6 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-116 - Improper Encoding or Escaping of Output

Assigner

CERT-PL

References

2 references

URL	Tags
https://cert.pl/en/posts/2026/08/CVE-2026-66484	third-party-advisory
https://git.savannah.gnu.org/cgit/cpio.git	product

Impacted products

1 product

Vendor	Product	Version
GNU	cpio	Affected: 0 , ≤ 2.15 (custom)

Credits

Michał Majchrowicz (AFINE Team) Marcin Wyczechowski (AFINE Team)

Show details on NVD website

JSON

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GHSA-P5W5-QCG3-G8GX

Vulnerability from github – Published: 2026-08-10 12:31 – Updated: 2026-08-10 12:31

Details

This issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30

Severity

4.6 (Medium)


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

Show details on source website

JSON

To clipboard

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  "affected": [],
  "aliases": [
    "CVE-2026-66486"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-116"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T11:17:27Z",
    "severity": "MODERATE"
  },
  "details": "GNU cpio is vulnerable to improper encoding or escaping of output in its archive member listing functionality. When listing archive members via cpio -it, member names are printed directly to output without quoting or escaping. An attacker can craft a cpio archive containing member names with embedded newline characters or ANSI escape sequences, causing forged listing entries or terminal control sequence injection when the listing is displayed.\n\n\n\n\nThis issue has been fixed in commit 2ff9600c9ef32e88759843cdbde74c8db5ae9b30",
  "id": "GHSA-p5w5-qcg3-g8gx",
  "modified": "2026-08-10T12:31:50Z",
  "published": "2026-08-10T12:31:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-66486"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/08/CVE-2026-66484"
    },
    {
      "type": "WEB",
      "url": "https://git.savannah.gnu.org/cgit/cpio.git"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/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"
    }
  ]
}

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.

Action not permitted

CVE-2026-66486 (GCVE-0-2026-66486)

GHSA-P5W5-QCG3-G8GX

Tags

Sightings

Nomenclature