CVE-2026-102998

pypdf: Possible long runtimes when generating appearance streams

HIGH
7.5
CVSS Score
Published: September 30, 2026 at 08:09 PM UTC
Updated: November 2, 2026 at 04:06 PM UTC
2 products affected across 2 vendorsPypdfPypdf

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Severity
HIGH7.5
Exploit prediction
EPSS 0.3%
SSVC
No known exploit

Description

pypdf is a free and open-source pure-python PDF library. Prior to 6.19.0, a crafted PDF with form field values can cause pypdf/generic/_appearance_stream.py appearance-stream generation to repeat invariant selection-data work inside a loop when an application updates fields with flattening enabled, resulting in excessive runtimes and application unavailability. This issue is fixed in version 6.19.0.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.19.0
Affected range stops below 6.19.0, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

x_refsource_CONFIRMVendor Advisory
Source: cverecord
https://github.com/py-pdf/pypdf/security/advisories/GHSA-php9-fj8v-98fj
x_refsource_MISCPatchIssue Tracking
Source: cverecord
https://github.com/py-pdf/pypdf/pull/4087
x_refsource_MISCRelease Notes
Source: cverecord
https://github.com/py-pdf/pypdf/releases/tag/6.19.0

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400

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