Fix CVE-2026-52858: possible code execution with python3complete

Backport two upstream commits to fix CVE-2026-52858, which
allowed possible code execution via import/from statements in
python3complete and pythoncomplete omni-completion plugins.

Patch 9.2.0561 disables execution of import/from statements
by default and adds a g:pythoncomplete_allow_import opt-in
variable. Patch 9.2.0568 fixes a bug where the vim module
was not imported in evalsource() scope, causing the opt-in
variable to silently have no effect.

CVE: CVE-2026-52858
Upstream patches:
 - 4b850457e1.patch
 - 868ad62cb8.patch
Resolves: RHEL-186651

This commit was backported by Ymir, a Red Hat Enterprise Linux software maintenance AI agent.

Assisted-by: Ymir
This commit is contained in:
RHEL Packaging Agent 2026-08-05 11:04:32 +00:00 committed by Zdenek Dohnal
parent e1c7040ec9
commit df0792b607
3 changed files with 257 additions and 1 deletions

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@ -0,0 +1,160 @@
From 3c2146726eba3d6e01138dd5a0af974cff902a6d Mon Sep 17 00:00:00 2001
From: Christian Brabandt <cb@256bit.org>
Date: Fri, 29 May 2026 19:05:53 +0000
Subject: [PATCH] patch 9.2.0561: [security]: possible code execution with
python3complete
Problem: [security]: possible code execution with python3complete
Solution: Disable execution of import/from statements
Github Security Advisory:
https://github.com/vim/vim/security/advisories/GHSA-52mc-rq6p-rc7c
Signed-off-by: Christian Brabandt <cb@256bit.org>
---
runtime/autoload/README.txt | 1 +
runtime/autoload/python3complete.vim | 17 ++++++++++++++---
runtime/autoload/pythoncomplete.vim | 17 ++++++++++++++---
runtime/doc/filetype.txt | 15 ++++++++++++++-
4 files changed, 43 insertions(+), 7 deletions(-)
diff --git a/runtime/autoload/README.txt b/runtime/autoload/README.txt
index 3b18d3dde..b22581963 100644
--- a/runtime/autoload/README.txt
+++ b/runtime/autoload/README.txt
@@ -17,6 +17,7 @@ htmlcomplete.vim HTML
javascriptcomplete.vim Javascript
phpcomplete.vim PHP
pythoncomplete.vim Python
+python3complete.vim Python
rubycomplete.vim Ruby
syntaxcomplete.vim from syntax highlighting
xmlcomplete.vim XML (uses files in the xml directory)
diff --git a/runtime/autoload/python3complete.vim b/runtime/autoload/python3complete.vim
index ea0a33136..aba341229 100644
--- a/runtime/autoload/python3complete.vim
+++ b/runtime/autoload/python3complete.vim
@@ -14,6 +14,10 @@
" i.e. "import url<c-x,c-o>"
" Continue parsing on invalid line??
"
+" v 0.10 by Vim project
+" * disables importing local modules, unless the global Vim variable
+" g:pythoncomplete_allow_import is set to non-zero
+"
" v 0.9
" * Fixed docstring parsing for classes and functions
" * Fixed parsing of *args and **kwargs type arguments
@@ -132,11 +136,20 @@ class Completer(object):
def evalsource(self,text,line=0):
sc = self.parser.parse(text,line)
+ try: allow_imports = int(
+ vim.eval("get(g:, 'pythoncomplete_allow_import', 0)"))
+ except Exception:
+ allow_imports = 0
src = sc.get_code()
dbg("source: %s" % src)
try: exec(src,self.compldict)
except: dbg("parser: %s, %s" % (sys.exc_info()[0],sys.exc_info()[1]))
for l in sc.locals:
+ # Executing import/from statements harvested from the buffer runs
+ # arbitrary package code; only do so when the user opted in.
+ if not allow_imports and (l.startswith('import')
+ or l.startswith('from ')):
+ continue
try: exec(l,self.compldict)
except: dbg("locals: %s, %s [%s]" % (sys.exc_info()[0],sys.exc_info()[1],l))
@@ -300,13 +313,11 @@ class Scope(object):
def get_code(self):
str = ""
if len(self.docstr) > 0: str += '"""'+self.docstr+'"""\n'
- for l in self.locals:
- if l.startswith('import'): str += l+'\n'
str += 'class _PyCmplNoType:\n def __getattr__(self,name):\n return None\n'
for sub in self.subscopes:
str += sub.get_code()
for l in self.locals:
- if not l.startswith('import'): str += l+'\n'
+ if not l.startswith('import') and not l.startswith('from '): str += l+'\n'
return str
diff --git a/runtime/autoload/pythoncomplete.vim b/runtime/autoload/pythoncomplete.vim
index aa28bb721..10147767e 100644
--- a/runtime/autoload/pythoncomplete.vim
+++ b/runtime/autoload/pythoncomplete.vim
@@ -12,6 +12,10 @@
" i.e. "import url<c-x,c-o>"
" Continue parsing on invalid line??
"
+" v 0.10 by Vim project
+" * disables importing local modules, unless the global Vim variable
+" g:pythoncomplete_allow_import is set to non-zero
+"
" v 0.9
" * Fixed docstring parsing for classes and functions
" * Fixed parsing of *args and **kwargs type arguments
@@ -146,11 +150,20 @@ class Completer(object):
def evalsource(self,text,line=0):
sc = self.parser.parse(text,line)
+ try: allow_imports = int(
+ vim.eval("get(g:, 'pythoncomplete_allow_import', 0)"))
+ except Exception:
+ allow_imports = 0
src = sc.get_code()
dbg("source: %s" % src)
try: exec(src) in self.compldict
except: dbg("parser: %s, %s" % (sys.exc_info()[0],sys.exc_info()[1]))
for l in sc.locals:
+ # Executing import/from statements harvested from the buffer runs
+ # arbitrary package code; only do so when the user opted in.
+ if not allow_imports and (l.startswith('import')
+ or l.startswith('from ')):
+ continue
try: exec(l) in self.compldict
except: dbg("locals: %s, %s [%s]" % (sys.exc_info()[0],sys.exc_info()[1],l))
@@ -315,13 +328,11 @@ class Scope(object):
def get_code(self):
str = ""
if len(self.docstr) > 0: str += '"""'+self.docstr+'"""\n'
- for l in self.locals:
- if l.startswith('import'): str += l+'\n'
str += 'class _PyCmplNoType:\n def __getattr__(self,name):\n return None\n'
for sub in self.subscopes:
str += sub.get_code()
for l in self.locals:
- if not l.startswith('import'): str += l+'\n'
+ if not l.startswith('import') and not l.startswith('from '): str += l+'\n'
return str
diff --git a/runtime/doc/filetype.txt b/runtime/doc/filetype.txt
index 4876e3d75..4b57e839f 100644
--- a/runtime/doc/filetype.txt
+++ b/runtime/doc/filetype.txt
@@ -740,7 +740,20 @@ By default the following options are set, in accordance with PEP8: >
To disable this behavior, set the following variable in your vimrc: >
let g:python_recommended_style = 0
-
+<
+Python omni-completion |compl-omni| is provided by python3complete.vim (or
+pythoncomplete.vim) for Vim builds with the |+python|/|+python3| interpreter.
+By default it does not inspect the import / from statements found in the
+buffer. This means completion of names defined in the buffer itself (classes,
+functions, variables) works, but completion of members of imported modules is
+not offered.
+
+To enable completion of imported module members, set: >
+ let g:pythoncomplete_allow_import = 1
+<
+WARNING: enabling this causes omni-completion to execute the import statements
+found in the buffer through Python's import machinery, which runs the imported
+modules' top-level code. Only enable this for code you trust.
QF QUICKFIX *qf.vim* *ft-qf-plugin*

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@ -0,0 +1,84 @@
From 9fbc96ad3e9d286ec5edf8c7700da8554dd39afb Mon Sep 17 00:00:00 2001
From: thinca <thinca@gmail.com>
Date: Sun, 31 May 2026 12:33:07 +0000
Subject: [PATCH] patch 9.2.0568: pythoncomplete: g:pythoncomplete_allow_import
had no effect
Problem: The security patch 9.2.0561 added a vim.eval() call inside
Completer.evalsource() to honor g:pythoncomplete_allow_import.
But the 'vim' module is only imported inside the outer
vimcomplete() / vimpy3complete() function, not at the script's
top level, so referring to it from a Completer method raises
NameError. The surrounding bare 'except' silently swallows
the error and leaves allow_imports at 0, meaning the opt-in
never takes effect -- 'import os' (and any other
buffer-level import) is always skipped, no candidates are
produced for 'os.<...>' and
Test_popup_and_preview_autocommand() fails on the Windows
CI matrix (Linux skips the test because Python 2 is absent).
Solution: Re-import 'vim' at the top of evalsource() in both
pythoncomplete.vim and python3complete.vim so the eval reads
the global, and set g:pythoncomplete_allow_import = 1 in the
test (it is the opt-in intended for callers that trust the
buffer contents) (thinca).
closes: #20386
Signed-off-by: thinca <thinca@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
---
runtime/autoload/python3complete.vim | 3 +++
runtime/autoload/pythoncomplete.vim | 3 +++
src/testdir/test_popup.vim | 4 ++++
3 files changed, 10 insertions(+)
diff --git a/runtime/autoload/python3complete.vim b/runtime/autoload/python3complete.vim
index aba341229..1c432f3c8 100644
--- a/runtime/autoload/python3complete.vim
+++ b/runtime/autoload/python3complete.vim
@@ -135,6 +135,9 @@ class Completer(object):
self.parser = PyParser()
def evalsource(self,text,line=0):
+ # vim is imported locally in vimpy3complete(); re-import here so the
+ # vim.eval() below works (otherwise NameError, silently caught).
+ import vim
sc = self.parser.parse(text,line)
try: allow_imports = int(
vim.eval("get(g:, 'pythoncomplete_allow_import', 0)"))
diff --git a/runtime/autoload/pythoncomplete.vim b/runtime/autoload/pythoncomplete.vim
index 10147767e..b4340f7ae 100644
--- a/runtime/autoload/pythoncomplete.vim
+++ b/runtime/autoload/pythoncomplete.vim
@@ -149,6 +149,9 @@ class Completer(object):
self.parser = PyParser()
def evalsource(self,text,line=0):
+ # vim is imported locally in vimcomplete(); re-import here so the
+ # vim.eval() below works (otherwise NameError, silently caught).
+ import vim
sc = self.parser.parse(text,line)
try: allow_imports = int(
vim.eval("get(g:, 'pythoncomplete_allow_import', 0)"))
diff --git a/src/testdir/test_popup.vim b/src/testdir/test_popup.vim
index 879d1fa3e..be27097a1 100644
--- a/src/testdir/test_popup.vim
+++ b/src/testdir/test_popup.vim
@@ -724,6 +724,9 @@ func Test_popup_and_preview_autocommand()
au!
au BufAdd * nested tab sball
augroup END
+ " Let pythoncomplete follow the buffer's 'import os' (off by default
+ " since v9.2.0561) so 'os.' can be completed.
+ let g:pythoncomplete_allow_import = 1
set omnifunc=pythoncomplete#Complete
call setline(1, 'import os')
" make the line long
@@ -746,6 +749,7 @@ func Test_popup_and_preview_autocommand()
augroup END
augroup! MyBufAdd
bw!
+ unlet g:pythoncomplete_allow_import
endfunc
func Test_popup_and_previewwindow_dump()

View File

@ -51,7 +51,7 @@ Summary: The VIM editor
URL: http://www.vim.org/
Name: vim
Version: %{baseversion}.%{patchlevel}
Release: 20%{?dist}
Release: 21%{?dist}
Epoch: 2
# swift.vim contains Apache 2.0 with runtime library exception:
# which is taken as Apache-2.0 WITH Swift-exception - reported to legal as https://gitlab.com/fedora/legal/fedora-license-data/-/issues/188
@ -181,6 +181,12 @@ Patch3029: 0001-patch-9.2.0653-security-out-of-bounds-write-in-tree_.patch
# https://redhat.atlassian.net/browse/RHEL-186663
# https://github.com/vim/vim/commit/f08ab2f4d7d2947c8dd6c179ae08ee6146a2694b
Patch3030: 0001-patch-9.2.0495-security-runtime-netrw-code-injectio.patch
# RHEL-186651 CVE-2026-52858 possible code execution with python3complete
# https://redhat.atlassian.net/browse/RHEL-186651
# https://github.com/vim/vim/commit/4b850457e12e1a678dd209f2868154f7553cbf8d
# https://github.com/vim/vim/commit/868ad62cb8bf8038322eab2badd31bd98b02b9df
Patch3031: 0001-patch-9.2.0561-security-possible-code-execution-with.patch
Patch3032: 0001-patch-9.2.0568-pythoncomplete-g-pythoncomplete_allow.patch
# uses autoconf in spec file
@ -529,6 +535,8 @@ perl -pi -e "s,bin/nawk,bin/awk,g" runtime/tools/mve.awk
%patch -P 3028 -p1 -b .runtime-ccomplete
%patch -P 3029 -p1 -b .tree-count-words-oob
%patch -P 3030 -p1 -b .netrw-hist-inject
%patch -P 3031 -p1 -b .python3complete-import
%patch -P 3032 -p1 -b .pythoncomplete-allow-import
%build
cd src
@ -1159,6 +1167,10 @@ touch %{buildroot}/%{_datadir}/%{name}/vimfiles/doc/tags
%changelog
* Wed Aug 05 2026 RHEL Packaging Agent <redhat-ymir-agent@redhat.com> - 2:9.1.083-21
- RHEL-186651 CVE-2026-52858 vim: possible code execution with
python3complete
* Wed Aug 05 2026 RHEL Packaging Agent <redhat-ymir-agent@redhat.com> - 2:9.1.083-20
- RHEL-186663 CVE-2026-47162 vim: code injection via
NetrwBookHistSave()