GHSA-763m-79hh-57f2
Fix: py-pdf/pypdf#3966GHSA-763m-79hh-57f2 is a CWE-834 vulnerability in pypdf. O3 Security confirms whether GHSA-763m-79hh-57f2 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
pypdf: Possible long runtimes/large memory usage when extracting XForm objects
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-763m-79hh-57f2.
Real-World Exposure
pypdfReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires extracting the text of a page with lots of XForm objects, where some of them might be re-used.
Patches
This has been fixed in pypdf==6.16.1.
Workarounds
If you cannot upgrade yet, consider applying the changes from PR #3966.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | pypdf | all versions | 6.16.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pypdf. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pypdf to 6.16.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-763m-79hh-57f2 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-763m-79hh-57f2 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-763m-79hh-57f2. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-763m-79hh-57f2 in your dependencies?
O3 detects GHSA-763m-79hh-57f2 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.