Pdfly: pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams (CVE-2026-48156)
A vulnerability in pdfly's pypdf component allows crafted PDFs with specific cross-reference stream values to cause long runtimes, potentially leading to denial of service. The issue arises when cross-reference streams contain /W [0 0 0] and large /Size values. This vulnerability has a low severity score and does not impact confidentiality or integrity.
AI Analysis
Technical Summary
CVE-2026-48156 describes a performance-related vulnerability in pdfly's pypdf library where an attacker can craft a PDF file with cross-reference streams specifying /W [0 0 0] and large /Size values. This causes the library to experience long runtimes when processing such files. The vulnerability has been addressed in pypdf version 6.12.0. For those unable to upgrade immediately, applying the changes from pull request #3791 is recommended as a workaround.
Potential Impact
The vulnerability can cause denial of service through prolonged processing times when handling maliciously crafted PDFs. It does not affect confidentiality or integrity, only availability due to long runtimes.
Mitigation Recommendations
Upgrade to pypdf version 6.12.0 or later, where this issue is fixed. If immediate upgrade is not possible, apply the changes from pull request #3791 as a temporary workaround.
Pdfly: pypdf: Possible long runtimes for zero-only width values in cross-reference streamsuntimes for zero-only width values in cross-reference streams (CVE-2026-48156)
Description
A vulnerability in pdfly's pypdf component allows crafted PDFs with specific cross-reference stream values to cause long runtimes, potentially leading to denial of service. The issue arises when cross-reference streams contain /W [0 0 0] and large /Size values. This vulnerability has a low severity score and does not impact confidentiality or integrity.
CVSS v3.1
Score 3.3low
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-48156 describes a performance-related vulnerability in pdfly's pypdf library where an attacker can craft a PDF file with cross-reference streams specifying /W [0 0 0] and large /Size values. This causes the library to experience long runtimes when processing such files. The vulnerability has been addressed in pypdf version 6.12.0. For those unable to upgrade immediately, applying the changes from pull request #3791 is recommended as a workaround.
Potential Impact
The vulnerability can cause denial of service through prolonged processing times when handling maliciously crafted PDFs. It does not affect confidentiality or integrity, only availability due to long runtimes.
Mitigation Recommendations
Upgrade to pypdf version 6.12.0 or later, where this issue is fixed. If immediate upgrade is not possible, apply the changes from pull request #3791 as a temporary workaround.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- BREW-pdfly-CVE-2026-48156
- Osv Schema Version
- 1.7.3
- Ecosystems
- ["Homebrew"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac1396ea43b0b3b89d5fde9
Added to database: 10/03/2026, 17:20:46 UTC
Last enriched: 10/03/2026, 17:26:27 UTC
Last updated: 10/03/2026, 22:36:47 UTC
Views: 4
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