CVE-2026-71870

Excessive memory consumption via unbounded ToUnicode tokens

Published Aug 7, 2026 · Updated Aug 7, 2026

Resource exhaustion in py-pdf pypdf before 6.15.0 allows attackers to consume excessive memory via a crafted PDF during text extraction. The parse_bfrange function in pypdf/_cmap.py decodes unbounded hexadecimal source-code and destination-string tokens from a font /ToUnicode CMap. Processing an untrusted PDF through text extraction is required; the published impact is large memory consumption, with no guaranteed crash reported.

CVSS severity4.8
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in py-pdf pypdf before 6.15.0 allows attackers to consume excessive memory via a crafted PDF during text extraction. The parse_bfrange function in pypdf/_cmap.py decodes unbounded hexadecimal source-code and destination-string tokens from a font /ToUnicode CMap. Processing an untrusted PDF through text extraction is required; the published impact is large memory consumption, with no guaranteed crash reported.

The record

CVE
CVE-2026-71870
Published
Aug 7, 2026
Updated
Aug 7, 2026
Vendor
py-pdf
Product
pypdf
Classifications
CWE-400, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 7, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 7, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.15.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

py-pdf · pypdfversion=< 6.15.0

Published CVSS scores

4.8GitHub CNACVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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