medium6.9
CVE-2026-27025
pypdf has possible long runtimes/large memory usage for large /ToUnicode streams
Impact
### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the `/ToUnicode` entry of a font with unusually large values, for example during text extraction. ### Patches This has been fixed in [pypdf==6.7.1](https://github.com/py-pdf/pypdf/releases/tag/6.7.1). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3646](https://github.com/py-pdf/pypdf/pull/3646).
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | pypdf | < 6.7.1 | 6.7.1 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Pypdf Project | Pypdf | before 6.7.1 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/py-pdf/pypdf/commit/77d7b8d7cfbe8dd179858dfa42666f73fc6e57a2
- https://github.com/py-pdf/pypdf/pull/3646
- https://github.com/py-pdf/pypdf/releases/tag/6.7.1
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-wgvp-vg3v-2xq3
- https://github.com/advisories/GHSA-wgvp-vg3v-2xq3
- https://nvd.nist.gov/vuln/detail/CVE-2026-27025