CVE-2023-27986Public exploit

Code execution via unescaped mailto URI quotes

Published Mar 9, 2023 · Updated Mar 5, 2025

Code injection in emacsclient-mail.desktop in GNU Emacs 28.1 through 28.2 allows local users to execute code via a crafted mailto URI. The desktop entry embeds the URI in an Emacs Lisp expression passed to emacsclient --eval without escaping embedded double quotes. Execution requires a user to activate the crafted URI through a desktop application that selects the vulnerable mailto handler; injected Lisp runs with the user’s privileges.

CVSS severity7.8
High
EPSS probability0.48%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Code injection in emacsclient-mail.desktop in GNU Emacs 28.1 through 28.2 allows local users to execute code via a crafted mailto URI. The desktop entry embeds the URI in an Emacs Lisp expression passed to emacsclient --eval without escaping embedded double quotes. Execution requires a user to activate the crafted URI through a desktop application that selects the vulnerable mailto handler; injected Lisp runs with the user’s privileges.

The record

CVE
CVE-2023-27986
Published
Mar 9, 2023
Updated
Mar 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-94, T1203, T1204.001
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 9, 2023CVE publishedPublication date reported by the CVE source.
  2. Mar 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
7.8CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
T1203Exploitation for Client Execution
T1204.001User Execution: Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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