CVE-2026-82398

mediumpriority · track · 21EPSS 0.005 · 44 %ileUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.52% (44th) EPSS
CVSS 5.3 · medium
Is it mine?
2 products
Check your exposure
Who says so?
2 sources
osv · nvd

EPSS · scored 2026-10-28

pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.

01

cvss

Technical severity, 0–10. One row per scoring source.

6.9
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.7–6.9

v3.15.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Lprimary · NVD / NIST USexploitability 3.9 · impact 1.4
v4.06.9mediumCVSS:4.0/AV:N/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:Xsecondary · security-advisories@github.com
v4.02.7lowCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/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:Xsecondary · CVSS-BT (t0sche)
02

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS
03

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-407USCWE-407US
04

affected products (2)

Products and version ranges known to be affected.

05

advisories (2)

Vendor and ecosystem advisories describing this.

  • GHSA-fc8x-2rww-xw9mpypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace2026-09-02ghsa · osvUS

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a call to `read_until_whitespace` with an input which does not have whitespace for a long time. ### Patches This has been fixed in [pypdf==6.15.0](https://github.com/py-pdf/pypdf/releases/tag/6.15.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3947](https://github.com/py-pdf/pypdf/pull/3947).

  • PYSEC-2026-3912pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace2026-09-10vendor · osvUS

    ### Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a call to `read_until_whitespace` with an input which does not have whitespace for a long time. ### Patches This has been fixed in [pypdf==6.15.0](https://github.com/py-pdf/pypdf/releases/tag/6.15.0). ### Workarounds If you cannot upgrade yet, consider applying the changes from PR [#3947](https://github.com/py-pdf/pypdf/pull/3947).

06

also known as (2)

Other names and identifiers for this entity.

07

sources

Which sources assert this record, and when.

osvnvdNVDCVE.orgMITRE
published 2026-08-31modified 2026-09-01
08

references (4) nvd

External citations — patches, advisories, analysis.

scry

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