PyPDF's Manipulated FlateDecode streams can exhaust RAM
Published Aug 13, 2025 · Updated Oct 23, 2026 · Also known as PYSEC-2026-1830, GHSA-7hfw-26vp-jp8m
Original summary
Normalized public record · Updated Oct 23, 2026
PyPDF's Manipulated FlateDecode streams can exhaust RAM
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access.
Potential impact
An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires just reading the file if a series of FlateDecode filters is used on a malicious cross-reference stream. Other content streams are affected on explicit access.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- MEDIUM
- Confidence
- 10%
- Aliases
- PYSEC-2026-1830, GHSA-7hfw-26vp-jp8m
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Aug 13, 2025 · Last refreshed Oct 23, 2026