CVE-2026-27026
pypdf possibly has long runtimes for malformed FlateDecode streams
5.5
MEDIUM
CVSS 3.1
EPSS 0.01%
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.7.1, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a malformed /FlateDecode stream, where the byte-by-byte decompression is used. This vulnerability is fixed in 6.7.1.
How to fix CVE-2026-27026
To remediate CVE-2026-27026, upgrade the affected package to a fixed version below.
- —no fix listed
- —no fix listed
- —upgrade to 6.7.1 or later
Is CVE-2026-27026 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0
- from 0
- from 0, < 6.7.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |