CVE-2026-48156: py-pdf pypdf Excessive Iteration
CVSS: 5.1v4.0MediumAnalyzed
AliasesGHSA-248m-82v9-q6g6PYSEC-2026-3004UBUNTU-CVE-2026-48156DEBIAN-CVE-2026-48156CGA-c6fr-q65w-ch32CGA-j896-x95p-p22pCGA-g8c5-5m99-rpgrCGA-xxgq-94cj-c235
Published 28-05-2026Last modified 30-05-2026
Vulnerability summary
CVE-2026-48156 is a medium (CVSS 5.1) Excessive Iteration vulnerability in py-pdf pypdf. EPSS estimates a 0.17% chance of exploitation in the next 30 days, higher than 6.2% of scored vulnerabilities.
CVSS score
5.1/10
010
Medium · v4.0 (CVE.org)EPSS score
0.17%
0%100%
Low · +0.05 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 0 · Related 1Timeline
- 28-05-2026PublishedVulnerability first disclosed.
- 30-05-2026Last modifiedVulnerability information updated.
Description
pypdf is a free and open-source pure-python PDF library. Prior to 6.12.0, an attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with /W [0 0 0] values and large /Size values. This vulnerability is fixed in 6.12.0.
CVSS metrics
10 scores · 7 sources · 2 versionsMedium 5.1Preferred score · CVE.org (CNA)
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:NSourcesAll 6 agree
- OSV · PypiEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · UbuntuEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · WolfiEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- OSV · ChainguardEcosystem advisory · calculated5.1MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- NVDNIST5.1MediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/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
Low 3.3Preferred score · OSV · Pypi (Ecosystem advisory) · calculated from vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:LSourcesAll 4 agree
- OSV · UbuntuEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- OSV · DebianEcosystem advisory · calculated3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
- NVDNIST3.3LowCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
EPSS trend
Probability
0.17%
Chance of exploitation in the next 30 days
Percentile
6%
Versus all other CVEs
30-day change
+0.05 pp
From 0.12% on 20-09-2026
20-09-202620-10-2026
EPSS score0.17%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard2 products
- litellm< 1.88.1-r1
- open-webui< 0.9.6-r4
Debian2 products
- pypdfAll versions (No fix recorded) | < 6.19.0-1
- pypdf2All versions (No fix recorded)
Ubuntu2 products
- pypdfAll versions (No fix recorded)
- pypdf2All versions (No fix recorded)
Py-pdf1 product
- pypdf< 6.12.0
Pypdf_project1 product
- pypdf< 6.12.0
PyPI1 product
- pypdf< 6.12.0
Wolfi1 product
- open-webui< 0.9.6-r4
7 vendors · 10 products
References
12 links- github.com/py-pdf/pypdf/security/advisories/GHSA-248m-82v9-q6g6X Refsource CONFIRMWEBREPORTAdvisoryPatchVendor Advisory
- github.com/py-pdf/pypdfPACKAGE
- pypi.org/project/pypdfPACKAGE
