GeezerVison

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

GeezerVison is showing github.com — [3.13] gh-90949: expose Expat API to tune exponential expansion protections (GH-139368) by StanFromIreland · Pull Request #151151 · python/cpython

Conversation

StanFromIreland commented Jun 9, 2026 •

edited by bedevere-app Bot

Loading

Uh oh!

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

Copy link

Copy Markdown

Member

Expose the XML Expat 2.7.2 APIs to tune protections against "billion laughs" 1 attacks.

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

parser.SetBillionLaughsAttackProtectionActivationThreshold(threshold), and
parser.SetBillionLaughsAttackProtectionMaximumAmplification(max_factor).

This completes the work in f04bea4, and improves the existing related documentation.

(cherry picked from commit 6661123)

Issue: Expose Expat XML attack protection APIs #90949

Sorry, something went wrong.

Uh oh!

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

All reactions


          [3.13] pythongh-90949: expose Expat API to tune exponential expansion…

37af8f0

… protections (pythonGH-139368) (python#150496)

Expose the XML Expat 2.7.2 APIs to tune protections against
"billion laughs" [1] attacks.

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

- `parser.SetBillionLaughsAttackProtectionActivationThreshold(threshold)`, and
- `parser.SetBillionLaughsAttackProtectionMaximumAmplification(max_factor)`.

This completes the work in f04bea4,
and improves the existing related documentation.

[1]: https://en.wikipedia.org/wiki/Billion_laughs_attack
(cherry picked from commit 6661123)

Co-authored-by: Bénédikt Tran <[email protected]>

bedevere-app Bot added the awaiting core review label

Jun 9, 2026

This was referenced Jun 9, 2026

Expose Expat XML attack protection APIs #90949

Closed

[3.14] gh-90949: expose Expat API to tune exponential expansion protections (GH-139368) #150496

Merged

StanFromIreland commented

Jun 9, 2026

View reviewed changes

Comment thread

Misc/NEWS.d/3.13.10.rst

StanFromIreland Jun 9, 2026

Copy link

Copy Markdown

Member Author

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.

Backport is cleanly from c078637, bar this file and the generated clinic.

Sorry, something went wrong.

Uh oh!

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

All reactions

StanFromIreland requested a review from picnixz

June 9, 2026 12:49

read-the-docs-community Bot commented Jun 9, 2026

Copy link

Copy Markdown

Documentation build overview

📚 cpython-previews | 🛠️ Build #33057787 | 📁 Comparing 37af8f0 against main (9fdbade)

🔍 Preview build

456 files changed · ± 417 modified · - 39 deleted

± Modified

- Deleted

All reactions

Sorry, something went wrong.

Uh oh!

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

StanFromIreland changed the title ~~[3.13] gh-90949: expose Expat API to tune exponential expansion protections (GH-139368) (#150496)~~ [3.13] gh-90949: expose Expat API to tune exponential expansion protections (GH-139368)

Jun 9, 2026

bedevere-app Bot mentioned this pull request

Jun 9, 2026

gh-90949: expose Expat API to tune exponential expansion protections #139368

Merged

StanFromIreland mentioned this pull request

Jun 9, 2026

[3.14] gh-149018: Use XML_SetHashSalt16Bytes in pyexpat/_elementtree when possible (GH-149023) #149646

Merged

picnixz approved these changes

Jun 9, 2026

View reviewed changes

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.

So only gen files and NEWS were manually changed? if so LGTM.

Sorry, something went wrong.

Uh oh!

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

StanFromIreland reacted with thumbs up emoji

All reactions

👍 1 reaction

bedevere-app Bot added awaiting merge and removed awaiting core review labels

Jun 9, 2026

StanFromIreland merged commit 19bc391 into python:3.13

Jun 9, 2026

45 of 48 checks passed

Uh oh!

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

bedevere-app Bot removed the awaiting merge label

Jun 9, 2026

StanFromIreland deleted the backport-c078637-3.13 branch

June 9, 2026 14:23

StanFromIreland added the needs backport to 3.12 only security fixes label

Jun 12, 2026

miss-islington-app Bot commented Jun 12, 2026

Copy link

Copy Markdown

Thanks @StanFromIreland for the PR 🌮🎉.. I'm working now to backport this PR to: 3.12.
🐍🍒⛏🤖

All reactions

Sorry, something went wrong.

Uh oh!

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

miss-islington-app Bot commented Jun 12, 2026

Copy link

Copy Markdown

Sorry, @StanFromIreland, I could not cleanly backport this to 3.12 due to a conflict.
Please backport using cherry_picker on command line.

cherry_picker 19bc39127e5c916c42c54487a1ae68be76582f50 3.12

All reactions

Sorry, something went wrong.

Uh oh!

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

miss-islington-app Bot assigned StanFromIreland

Jun 12, 2026

StanFromIreland commented Jun 12, 2026

Copy link

Copy Markdown

Member Author

Oh right, the NEWS files.

All reactions

Sorry, something went wrong.

Uh oh!

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

StanFromIreland removed the needs backport to 3.12 only security fixes label

Jun 12, 2026

Reviewers

picnixz

picnixz approved these changes

Uh oh!

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

Assignees

StanFromIreland

Labels

None yet

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.

2 participants

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.

GeezerVison

Conversation

StanFromIreland commented Jun 9, 2026 • edited by bedevere-app Bot Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Uh oh!

StanFromIreland Jun 9, 2026

Choose a reason for hiding this comment

Uh oh!

read-the-docs-community Bot commented Jun 9, 2026

Documentation build overview

Uh oh!

picnixz left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

miss-islington-app Bot commented Jun 12, 2026

Uh oh!

miss-islington-app Bot commented Jun 12, 2026

Uh oh!

StanFromIreland commented Jun 12, 2026

Uh oh!

Reviewers

Uh oh!

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

StanFromIreland commented Jun 9, 2026 •

edited by bedevere-app Bot

Loading

Uh oh!

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