Vulnerability-Lookup

GHSA-39P3-JW8M-JMR7

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

Details

GNU Emacs for Android is vulnerable to an integer overflow in the sfnt_read_cmap_format_12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. An attacker can deliver a malicious font file via email, EWW (Emacs Web Wowser), or documents with custom faces, causing Emacs to load it. This results in heap memory corruption that can lead to code execution.

This issue was fixed in commit c4e20777c26548722a37b03db93243e83a0d6188

Severity

5.3 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-71392"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-190"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-10T11:17:28Z",
    "severity": "MODERATE"
  },
  "details": "GNU Emacs for Android is vulnerable to an integer overflow in the sfnt_read_cmap_format_12() function in src/sfnt.c. When processing a crafted TrueType font file, an unguarded addition in the xmalloc allocation call wraps around on 32-bit builds, causing a heap buffer overflow write. An attacker can deliver a malicious font file via email, EWW (Emacs Web Wowser), or documents with custom faces, causing Emacs to load it. This\u00a0results in heap memory corruption that can lead to code execution.\n\n\nThis issue was fixed in commit c4e20777c26548722a37b03db93243e83a0d6188",
  "id": "GHSA-39p3-jw8m-jmr7",
  "modified": "2026-08-10T12:31:51Z",
  "published": "2026-08-10T12:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-71392"
    },
    {
      "type": "WEB",
      "url": "https://cert.pl/en/posts/2026/08/CVE-2026-71391"
    },
    {
      "type": "WEB",
      "url": "https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=c4e20777c26548722a37b03db93243e83a0d6188"
    },
    {
      "type": "WEB",
      "url": "https://www.gnu.org/savannah-checkouts/gnu/emacs/emacs.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:L/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"
    }
  ]
}

CVE-2026-71392 (GCVE-0-2026-71392)

Vulnerability from cvelistv5 – Published: 2026-08-10 10:22 – Updated: 2026-08-10 17:48 X_Open Source

Title

Integer Overflow in GNU Emacs for Android

Summary

Severity

5.3 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-10 17:48 UTC

CWE

CWE-190 - Integer Overflow or Wraparound

Assigner

CERT-PL ENISA root

References

3 references

URL	Tags
https://cert.pl/en/posts/2026/08/CVE-2026-71391	third-party-advisory
https://www.gnu.org/savannah-checkouts/gnu/emacs/…	product
https://git.savannah.gnu.org/cgit/emacs.git/commi…	patch

Impacted products

1 product

Vendor	Product	Version
GNU	Emacs	Affected: 0 , ≤ 30.2 (custom) cpe:2.3:a:gnu:emacs:::android:::::* cpe:2.3:a:gnu:emacs:::32_bit:::::*

Credits

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

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JSON

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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.

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.
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GHSA-39P3-JW8M-JMR7

CVE-2026-71392 (GCVE-0-2026-71392)

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