CVE-2026-27888: py-pdf pypdf Uncontrolled Resource Consumption
Vulnerability summary
CVE-2026-27888 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in py-pdf pypdf. EPSS estimates a 0.66% chance of exploitation in the next 30 days, higher than 50.6% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 2 · Related 2Timeline
- 26-02-2026PublishedVulnerability first disclosed.
- 23-06-2026Last modifiedVulnerability information updated.
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 metrics
7 scores · 5 sources · 2 versions- OSV · PypiEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- OSV · UbuntuEcosystem advisory · calculated8.7HighCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:UDiffers
- NVDNIST6.6MediumCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.66%
Chance of exploitation in the next 30 days
Percentile
51%
Versus all other CVEs
30-day change
+0.31 pp
From 0.35% on 20-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Debian2 products
- pypdfAll versions (No fix recorded) | < 6.9.0-1
- pypdf2All versions (No fix recorded)
Py-pdf1 product
- pypdf< 6.7.3
Pypdf_project1 product
- pypdf< 6.7.3
PyPI1 product
- pypdf< 6.7.3
Ubuntu1 product
- pypdfAll versions (No fix recorded)
5 vendors · 6 products
References
11 links- github.com/py-pdf/pypdf/security/advisories/GHSA-x7hp-r3qg-r3cjX Refsource CONFIRMWEBREPORTPatchVendor Advisory
- github.com/py-pdf/pypdf/commit/7a4c8246ed48d9d328fb596942271da47b6d109cX Refsource MISCWEBREPORTPatch
- github.com/py-pdf/pypdfPACKAGE
- pypi.org/project/pypdfPACKAGE
