CVE-2026-27888: CWE-400: Uncontrolled Resource Consumption in py-pdf pypdf
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
AI Analysis
Technical Summary
The vulnerability CVE-2026-27888 in pypdf (a pure-python PDF library) allows an attacker to cause uncontrolled resource consumption leading to RAM exhaustion. This occurs when a crafted PDF file contains an XFA stream compressed with /FlateDecode, and the xfa property of a PDF reader or writer is accessed. The flaw affects all pypdf versions prior to 6.7.3 and has been addressed by an official fix in version 6.7.3.
Potential Impact
An attacker can cause a denial-of-service condition by exhausting the system's RAM when processing malicious PDF files that exploit this vulnerability. This could disrupt applications or services using vulnerable versions of pypdf by making them unresponsive or crashing due to resource exhaustion.
Mitigation Recommendations
Upgrade to pypdf version 6.7.3 or later, where this vulnerability has been fixed. As a temporary workaround, manually apply the patch if upgrading is not immediately possible. No other vendor advisories indicate alternative mitigations or that no action is required.
CVE-2026-27888: CWE-400: Uncontrolled Resource Consumption in py-pdf pypdf
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.3, an attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing the `xfa` property of a reader or writer and the corresponding stream being compressed using `/FlateDecode`. This has been fixed in pypdf 6.7.3. As a workaround, apply the patch manually.
CVSS v4.0
Score 6.6medium
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability CVE-2026-27888 in pypdf (a pure-python PDF library) allows an attacker to cause uncontrolled resource consumption leading to RAM exhaustion. This occurs when a crafted PDF file contains an XFA stream compressed with /FlateDecode, and the xfa property of a PDF reader or writer is accessed. The flaw affects all pypdf versions prior to 6.7.3 and has been addressed by an official fix in version 6.7.3.
Potential Impact
An attacker can cause a denial-of-service condition by exhausting the system's RAM when processing malicious PDF files that exploit this vulnerability. This could disrupt applications or services using vulnerable versions of pypdf by making them unresponsive or crashing due to resource exhaustion.
Mitigation Recommendations
Upgrade to pypdf version 6.7.3 or later, where this vulnerability has been fixed. As a temporary workaround, manually apply the patch if upgrading is not immediately possible. No other vendor advisories indicate alternative mitigations or that no action is required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-02-24T15:19:29.716Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 699f9a40b7ef31ef0b726103
Added to database: 02/26/2026, 00:56:32 UTC
Last enriched: 06/24/2026, 15:07:46 UTC
Last updated: 07/31/2026, 19:22:58 UTC
Views: 287
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