PYSEC-2026-3019
pypdf: manipulated stream length values can exhaust RAM
At a glance
- Published
- Updated
- CVE
- CVE-2026-31826
- Aliases
- GHSA-hqmh-ppp3-xvm7
- CVSS_V4
- CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Description
### Impact An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing a content stream with a rather large `/Length` value, regardless of the actual data length inside the stream. ### Patches This has been fixed in [pypdf==6.8.0](https://github.com/py-pdf/pypdf/releases/tag/6.8.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3675](https://github.com/py-pdf/pypdf/pull/3675). As far as we are aware, this mostly affects reading from buffers of unknown size, as returned by `open("file.pdf", mode="rb")` for example. Passing a file path or a `BytesIO` buffer to *pypdf* instead does not seem to trigger the vulnerability.
Affected packages
| Package | Versions |
|---|---|
| PyPI · pypdf | introduced 0, fixed 6.8.0 |
References
- https://github.com/py-pdf/pypdf/security/advisories/GHSA-hqmh-ppp3-xvm7 WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-31826 ADVISORY
- https://github.com/py-pdf/pypdf/pull/3675 WEB
- https://github.com/py-pdf/pypdf/commit/3c550b3196adeba1506a26e57c09c09fac75e9aa WEB
- https://github.com/py-pdf/pypdf PACKAGE
- https://github.com/py-pdf/pypdf/releases/tag/6.8.0 WEB
- https://pypi.org/project/pypdf PACKAGE
- https://github.com/advisories/GHSA-hqmh-ppp3-xvm7 ADVISORY
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — PyPA Advisory Database |