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Fencer Vulns
high 7.8

CVE-2023-27986 json

emacsclient-mail.desktop in Emacs 28.1 through 28.2 is vulnerable to Emacs Lisp code injections through a crafted mailto: URI with unescape…

published 2023-03-09 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-31712

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

emacsclient-mail.desktop in Emacs 28.1 through 28.2 is vulnerable to Emacs Lisp code injections through a crafted mailto: URI with unescaped double-quote characters. It is fixed in 29.0.90.

Patch / fix

  • emacs Debian 14, Debian 13, Debian 12 1:28.2+1-13

debian advisories DEBIAN-CVE-2023-27986

  • emacs openSUSE Tumbleweed 28.2-3.1

opensuse advisories openSUSE-SU-2024:12777-1

  • emacs Alpine 3.17 28.2-r3
  • emacs Alpine 3.24, Alpine 3.23, Alpine 3.22 +4 more 28.2-r6

alpine advisories ALPINE-CVE-2023-27986

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • emacs CBL-Mariner 2.0 28.2-4

azure linux advisories AZL-25603

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-27986 updated cvss 7.8

emacs: Emacs Lisp code injection via a crafted mailto URI

  • Red Hat Enterprise Linux 6 emacs, emacs-el, emacs-nox, emacs-common Red Hat Enterprise Linux 7 emacs, emacs-el, emacs-nox, emacs-common, emacs-terminal, emacs-filesystem Red Hat Enterprise Linux 8 emacs, emacs-nox, emacs-lucid, emacs-common, emacs-terminal, emacs-filesystem Red Hat Enterprise Linux 9 emacs, emacs-nox, emacs-lucid, emacs-common, emacs-filesystem
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
20 mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Classification

Weakness
  • CWE-94 Improper Control of Generation of Code

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.