Commit: patch 9.2.0839: [security]: arbitrary code execution via keyword lookup

[Christian Brabandt]

patch 9.2.0839: [security]: arbitrary code execution via keyword lookup

Commit: https://github.com/vim/vim/commit/c5a82fe013e73c98004ad7cd4f906b1ad1ed610e
Author: Yasuhiro Matsumoto <matt...@gmail.com>
Date: Thu Jul 23 19:13:15 2026 +0000

patch 9.2.0839: [security]: arbitrary code execution via keyword lookup

Problem: [security]: arbitrary code execution via keyword lookup in
sh.vim, zsh.vim and ps1.vim filetype plugin
(manus-use)
Solution: For powershell, quote the commands using single quotes, for
sh/zsh pass the argument as a separate list item to term_start()/system()
(Yasuhiro Matsumoto).

Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-r5v6-q6j8-8qw2

Signed-off-by: Yasuhiro Matsumoto <matt...@gmail.com>
Signed-off-by: Christian Brabandt <c...@256bit.org>

diff --git a/runtime/ftplugin/ps1.vim b/runtime/ftplugin/ps1.vim
index f1fe78df4..9ff764a28 100644
--- a/runtime/ftplugin/ps1.vim
+++ b/runtime/ftplugin/ps1.vim
@@ -6,6 +6,7 @@
" 2024 May 23 by Riley Bruins <rib...@gmail.com> ('commentstring')
" 2024 Sep 19 by Konfekt (simplify keywordprg #15696)
" 2025 Jul 22 by phanium (use :hor term #17822)
+" 2026 Jul 10 by Vim Project (quote K argument, prevent command injection)

" Only do this when not done yet for this buffer
if exists("b:did_ftplugin") | finish | endif
@@ -52,9 +53,9 @@ endif

if exists('s:pwsh_cmd')
if exists(':terminal') == 2
- command! -buffer -nargs=1 GetHelp silent exe 'hor term ' . s:pwsh_cmd . ' -NoLogo -NoProfile -NonInteractive -ExecutionPolicy RemoteSigned -Command Get-Help -Full "<args>"' . (executable('less') ? ' | less' : '')
+ command! -buffer -nargs=1 GetHelp call term_start([s:pwsh_cmd, '-NoLogo', '-NoProfile', '-NonInteractive', '-ExecutionPolicy', 'RemoteSigned', '-Command', "Get-Help -Full '" . substitute(<q-args>, "'", "''", 'g') . "'" . (executable('less') ? ' | less' : '')])
else
- command! -buffer -nargs=1 GetHelp echo system(s:pwsh_cmd . ' -NoLogo -NoProfile -NonInteractive -ExecutionPolicy RemoteSigned -Command Get-Help -Full <args>')
+ command! -buffer -nargs=1 GetHelp echo system([s:pwsh_cmd, '-NoLogo', '-NoProfile', '-NonInteractive', '-ExecutionPolicy', 'RemoteSigned', '-Command', "Get-Help -Full '" . substitute(<q-args>, "'", "''", 'g') . "'"])
endif
setlocal keywordprg=:GetHelp
let b:undo_ftplugin ..= " | setl kp< | sil! delc -buffer GetHelp"
diff --git a/runtime/ftplugin/sh.vim b/runtime/ftplugin/sh.vim
index 18cd219cd..45e6f44fc 100644
--- a/runtime/ftplugin/sh.vim
+++ b/runtime/ftplugin/sh.vim
@@ -8,6 +8,7 @@
" 2024 Dec 29 by Vim Project (improve setting shellcheck compiler)
" 2025 Mar 09 by Vim Project (set b:match_skip)
" 2025 Jul 22 by phanium (use :hor term #17822)
+" 2026 Jul 10 by Vim Project (pass K argument as a list, prevent shell injection)

if exists("b:did_ftplugin")
finish
@@ -54,9 +55,9 @@ let s:is_kornshell = get(b:, "is_kornshell", get(g:, "is_kornshell", 0))

if s:is_bash
if exists(':terminal') == 2
- command! -buffer -nargs=1 ShKeywordPrg silent exe ':hor term bash -c "help "<args>" 2>/dev/null || man "<args>""'
+ command! -buffer -nargs=1 ShKeywordPrg call term_start(['bash', '-c', 'help "$1" 2>/dev/null || man "$1"', '--', <q-args>])
else
- command! -buffer -nargs=1 ShKeywordPrg echo system('bash -c "help <args>" 2>/dev/null || MANPAGER= man "<args>"')
+ command! -buffer -nargs=1 ShKeywordPrg echo system(['bash', '-c', 'help "$1" 2>/dev/null || MANPAGER= man "$1"', '--', <q-args>])
endif
setlocal keywordprg=:ShKeywordPrg
let b:undo_ftplugin ..= " | setl kp< | sil! delc -buffer ShKeywordPrg"
diff --git a/runtime/ftplugin/zsh.vim b/runtime/ftplugin/zsh.vim
index 850bef055..816358593 100644
--- a/runtime/ftplugin/zsh.vim
+++ b/runtime/ftplugin/zsh.vim
@@ -2,7 +2,7 @@
" Language: Zsh shell script
" Maintainer: Christian Brabandt <c...@256bit.org>
" Previous Maintainer: Nikolai Weibull <n...@bitwi.se>
-" Latest Revision: 2025 Jul 23
+" Latest Revision: 2026 Jul 23
" License: Vim (see :h license)
" Repository: https://github.com/chrisbra/vim-zsh

@@ -25,9 +25,9 @@ endif

if executable('zsh') && &shell !~# '/\%(nologin\|false\)$'
if exists(':terminal') == 2
- command! -buffer -nargs=1 ZshKeywordPrg silent exe ':hor :term zsh -c "autoload -Uz run-help; run-help <args>"'
- else
- command! -buffer -nargs=1 ZshKeywordPrg echo system('MANPAGER= zsh -c "autoload -Uz run-help; run-help <args> 2>/dev/null"')
+ command! -buffer -nargs=1 ZshKeywordPrg call term_start(['zsh', '-c', 'autoload -Uz run-help; run-help "$1"', '--', <q-args>])
+ elseif has("patch-9.2.0250")
+ command! -buffer -nargs=1 ZshKeywordPrg echo system(['zsh', '-c', 'autoload -Uz run-help; MANPAGER= run-help "$1" 2>/dev/null', '--', <q-args>])
endif
setlocal keywordprg=:ZshKeywordPrg
let b:undo_ftplugin .= '| setl keywordprg< | sil! delc -buffer ZshKeywordPrg'
diff --git a/src/version.c b/src/version.c
index 07772b03f..9d3c95b00 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@ static char *(features[]) =

static int included_patches[] =
{ /* Add new patch number below this line */
+/**/
+ 839,
/**/
838,
/**/