Pdfly: pypdf: Possible large memory usage for large /ToUnicode streams (CVE-2026-71870)
A vulnerability in pdfly's pypdf component allows crafted PDF files with large /ToUnicode font streams to cause excessive memory usage during parsing, such as in text extraction. This issue has been fixed in pypdf version 6.15.0. Users unable to upgrade immediately can apply the changes from the referenced pull request as a workaround.
AI Analysis
Technical Summary
CVE-2026-71870 describes a vulnerability in the pdfly product's pypdf library where parsing the /ToUnicode entry of a font with unusually large values can lead to large memory consumption. This occurs during operations like text extraction. The vulnerability has been addressed and fixed in pypdf version 6.15.0. A workaround is available by applying the changes from pull request #3944 if upgrading is not yet possible.
Potential Impact
An attacker can craft a malicious PDF that triggers large memory consumption on the target system when the /ToUnicode font entry is parsed. This could potentially lead to denial of service conditions due to resource exhaustion. No information indicates privilege escalation or code execution.
Mitigation Recommendations
Upgrade to pypdf version 6.15.0 or later where the vulnerability is fixed. If upgrading is not feasible immediately, apply the changes from pull request #3944 as a temporary workaround.
Pdfly: pypdf: Possible large memory usage for large /ToUnicode streams (CVE-2026-71870)
Description
A vulnerability in pdfly's pypdf component allows crafted PDF files with large /ToUnicode font streams to cause excessive memory usage during parsing, such as in text extraction. This issue has been fixed in pypdf version 6.15.0. Users unable to upgrade immediately can apply the changes from the referenced pull request as a workaround.
CVSS v4.0
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-71870 describes a vulnerability in the pdfly product's pypdf library where parsing the /ToUnicode entry of a font with unusually large values can lead to large memory consumption. This occurs during operations like text extraction. The vulnerability has been addressed and fixed in pypdf version 6.15.0. A workaround is available by applying the changes from pull request #3944 if upgrading is not yet possible.
Potential Impact
An attacker can craft a malicious PDF that triggers large memory consumption on the target system when the /ToUnicode font entry is parsed. This could potentially lead to denial of service conditions due to resource exhaustion. No information indicates privilege escalation or code execution.
Mitigation Recommendations
Upgrade to pypdf version 6.15.0 or later where the vulnerability is fixed. If upgrading is not feasible immediately, apply the changes from pull request #3944 as a temporary workaround.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- BREW-pdfly-CVE-2026-71870
- Osv Schema Version
- 1.7.3
- Ecosystems
- ["Homebrew"]
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac1396ca43b0b3b89d5fdd6
Added to database: 10/03/2026, 17:20:44 UTC
Last enriched: 10/03/2026, 17:25:52 UTC
Last updated: 10/04/2026, 02:46:06 UTC
Views: 3
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