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 — [3.14] gh-145264: Do not ignore excess Base64 data after the first padded quad (GH-145267) by serhiy-storchaka · Pull Request #146326 · python/cpython

Conversation

@serhiy-storchaka

@serhiy-storchaka serhiy-storchaka commented Mar 23, 2026 •
edited by bedevere-app Bot
Loading

Uh oh!

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

Copy link
Copy Markdown
Member

Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc) no longer ignores excess data after the first padded quad in non-strict (default) mode. Instead, in conformance with RFC 4648, it ignores the pad character, "=", if it is present before the end of the encoded data.
(cherry picked from commit 4561f64)

  • Issue: Excess Base64 data ignored after padding by default #145264

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
All reactions
@serhiy-storchaka
[3.14] pythongh-145264: Do not ignore excess Base64 data after the fi…
a21e7ff 
…rst padded quad (pythonGH-145267)

Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc)
no longer ignores excess data after the first padded quad in non-strict
(default) mode.  Instead, in conformance with RFC 4648, it ignores the
pad character, "=", if it is present before the end of the encoded data.
(cherry picked from commit 4561f64)

Co-authored-by: Serhiy Storchaka <[email protected]>
@serhiy-storchaka serhiy-storchaka added the needs backport to 3.13 only security fixes label Mar 23, 2026
@bedevere-app bedevere-app Bot added the awaiting core review label Mar 23, 2026
This was referenced Mar 23, 2026
gh-145264: Do not ignore excess Base64 data after the first padded quad #145267
Merged
Excess Base64 data ignored after padding by default #145264
Closed
@ambv
ambv merged commit e31c551 into python:3.14 Mar 23, 2026
51 checks passed

Uh oh!

There was an error while loading. Please reload this page.
@miss-islington-app

miss-islington-app Bot commented Mar 23, 2026

Copy link
Copy Markdown

Thanks @serhiy-storchaka for the PR, and @ambv for merging it 🌮🎉.. I'm working now to backport this PR to: 3.13.
🐍🍒⛏🤖
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot removed the awaiting core review label Mar 23, 2026
miss-islington pushed a commit to miss-islington/cpython that referenced this pull request Mar 23, 2026
@serhiy-storchaka @miss-islington
[3.14] pythongh-145264: Do not ignore excess Base64 data after the fi…
bd4ab52 
…rst padded quad (pythonGH-145267) (pythonGH-146326)

Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc)
no longer ignores excess data after the first padded quad in non-strict
(default) mode.  Instead, in conformance with RFC 4648, it ignores the
pad character, "=", if it is present before the end of the encoded data.
(cherry picked from commit 4561f64)
(cherry picked from commit e31c551)

Co-authored-by: Serhiy Storchaka <[email protected]>
@bedevere-app

bedevere-app Bot commented Mar 23, 2026

Copy link
Copy Markdown

GH-146348 is a backport of this pull request to the 3.13 branch.
All reactions

Sorry, something went wrong.

Uh oh!

There was an error while loading. Please reload this page.
@bedevere-app bedevere-app Bot removed the needs backport to 3.13 only security fixes label Mar 23, 2026
ambv pushed a commit that referenced this pull request Mar 23, 2026
@miss-islington @serhiy-storchaka
[3.13] gh-145264: Do not ignore excess Base64 data after the first pa…
1f9958f 
…dded quad (GH-145267) (GH-146326) (GH-146348)

Base64 decoder (see binascii.a2b_base64(), base64.b64decode(), etc)
no longer ignores excess data after the first padded quad in non-strict
(default) mode.  Instead, in conformance with RFC 4648, it ignores the
pad character, "=", if it is present before the end of the encoded data.
(cherry picked from commit 4561f64)
(cherry picked from commit e31c551)

Co-authored-by: Serhiy Storchaka <[email protected]>
@serhiy-storchaka
serhiy-storchaka deleted the backport-4561f64-3.14 branch July 1, 2026 16:46
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

No reviews

Uh oh!

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

Assignees

No one assigned

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

@serhiy-storchaka @ambv
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.