GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — [3.12] gh-90949: add Expat API to prevent XML deadly allocations (CVE-2025-59375) (GH-139234) by hartwork · Pull Request #139527 · python/cpython

Conversation

@hartwork

@hartwork hartwork commented Oct 2, 2025 •
edited by github-actions Bot
Loading

Uh oh!

There was an error while loading. Please reload this page.

Copy link
Copy Markdown
Contributor

Expose the XML Expat 2.7.2 mitigation APIs to disallow use of disproportional amounts of dynamic memory from within an Expat parser (see CVE-2025-59375 for instance).

The exposed APIs are available on Expat parsers, that is, parsers created by xml.parsers.expat.ParserCreate(), as:

  • parser.SetAllocTrackerActivationThreshold(threshold), and
  • parser.SetAllocTrackerMaximumAmplification(max_factor).

(cherry picked from commit f04bea4)

CC @picnixz

  • Issue: Expose Expat XML attack protection APIs #90949

📚 Documentation preview 📚: https://cpython-previews--139527.org.readthedocs.build/

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
All reactions
picnixz and others added 4 commits October 2, 2025 23:47
@picnixz @hartwork
[3.12] pythongh-90949: add Expat API to prevent XML deadly allocations (
aeefb63 
CVE-2025-59375) (pythonGH-139234)

Expose the XML Expat 2.7.2 mitigation APIs to disallow use of
disproportional amounts of dynamic memory from within an Expat
parser (see CVE-2025-59375 for instance).

The exposed APIs are available on Expat parsers, that is,
parsers created by `xml.parsers.expat.ParserCreate()`, as:

- `parser.SetAllocTrackerActivationThreshold(threshold)`, and
- `parser.SetAllocTrackerMaximumAmplification(max_factor)`.
(cherry picked from commit f04bea4)

Co-authored-by: Bénédikt Tran <[email protected]>
@picnixz @hartwork
pythongh-90949: amend pythonGH-139234 in prevision of future mitigati…
a5d026a 
…on API (python#139366)

Fix some typos left in f04bea4,
and simplify some internal functions to ease maintenance of future
mitigation APIs.

(cherry picked from commit 68a1778)
@hartwork
Make use of macro _Py_ID possible to pyexpat
2ab3e1d
@hartwork
Add a temporary workaround for issue 139400
ce64f57
@bedevere-app bedevere-app Bot mentioned this pull request Oct 2, 2025
Expose Expat XML attack protection APIs #90949
Closed
@bedevere-app bedevere-app Bot added the awaiting review label Oct 2, 2025
@bedevere-app bedevere-app Bot mentioned this pull request Oct 2, 2025
gh-90949: add Expat API to prevent XML deadly allocations #139234
Merged
@bedevere-app bedevere-app Bot added the topic-XML label Oct 2, 2025
hartwork added 4 commits October 3, 2025 02:40
@hartwork
Add an empty commit to see how temporary the RTD CI fail is
56896ae
@hartwork
Revert introduction of stddef.h import
6e97592 
Idea by @picnixz
@hartwork
Merge remote-tracking branch 'upstream/3.12' into backport-f04bea4-3.12
bcab187
@hartwork
Drop workaround for 139400 as no-longer-needed
932d28d
@picnixz

picnixz commented Oct 7, 2025

Copy link
Copy Markdown
Member

To have a good synchronization, we'll also delay 3.10 to 3.13 backports for their next release cycle (see #139359 (comment)).
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@picnixz picnixz self-assigned this Oct 7, 2025
@ambv ambv added the DO-NOT-MERGE label Oct 8, 2025
@ambv

ambv commented Oct 8, 2025

Copy link
Copy Markdown
Contributor

I set DO-NOT-MERGE to avoid confusion. Unset that when you think we should be releasing this.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@picnixz picnixz removed the DO-NOT-MERGE label Nov 2, 2025
@hartwork
Merge remote-tracking branch 'upstream/3.12' into backport-f04bea4-3.12
e49766f
picnixz
picnixz approved these changes Nov 8, 2025
View reviewed changes

@picnixz picnixz left a comment

Copy link
Copy Markdown
Member

There was a problem hiding this comment.

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

The 22 additional lines are in the clinic file so all good.

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
hartwork reacted with thumbs up emoji
All reactions
  • 👍 1 reaction
@bedevere-app bedevere-app Bot added awaiting merge and removed awaiting review labels Nov 8, 2025
@picnixz
picnixz requested review from Yhg1s and removed request for Yhg1s November 8, 2025 13:47
@picnixz picnixz assigned Yhg1s Nov 8, 2025
@hartwork

hartwork commented Nov 22, 2025

Copy link
Copy Markdown
Contributor Author

@Yhg1s do you have a minute for this? 🙏
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@hartwork

hartwork commented Dec 17, 2025

Copy link
Copy Markdown
Contributor Author

@Yhg1s do you have a minute? 🙏
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@Yhg1s
Yhg1s merged commit 0e4cd89 into python:3.12 Dec 17, 2025
7 checks passed

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot removed the awaiting merge label Dec 17, 2025
@hartwork

hartwork commented Dec 17, 2025

Copy link
Copy Markdown
Contributor Author

Thanks! 🙏
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@picnixz picnixz picnixz approved these changes

Uh oh!

There was an error while loading. Please reload this page.

Assignees

@Yhg1s Yhg1s

@picnixz picnixz

Labels

topic-XML

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

Uh oh!

There was an error while loading. Please reload this page.

4 participants

@hartwork @picnixz @ambv @Yhg1s
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
You are visitor 01402503 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.