CVE-2026-31938Public exploitNetwork attack vector

Script execution via unsanitized new-window options

Published Mar 18, 2026 · Updated Mar 18, 2026

HTML injection in jsPDF before 4.2.1 allows remote attackers to execute scripts in a victim's browser through crafted output options. The output method inserts pdfObjectUrl, pdfJsUrl, filename, or the serialized options object into new-window HTML without contextual encoding, allowing markup to become executable script. Exploitation requires an application to accept attacker-controlled options, pass them to a vulnerable new-window overload, and induce a victim to create and open the PDF; resulting script can read or modify browser-context secrets.

CVSS severity9.6
Critical
EPSS probability0.26%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

HTML injection in jsPDF before 4.2.1 allows remote attackers to execute scripts in a victim's browser through crafted output options. The output method inserts pdfObjectUrl, pdfJsUrl, filename, or the serialized options object into new-window HTML without contextual encoding, allowing markup to become executable script. Exploitation requires an application to accept attacker-controlled options, pass them to a vulnerable new-window overload, and induce a victim to create and open the PDF; resulting script can read or modify browser-context secrets.

The record

CVE
CVE-2026-31938
Published
Mar 18, 2026
Updated
Mar 18, 2026
Vendor
Parallax
Product
jsPDF
Classifications
CWE-79, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=< 4.2.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Parallax · jsPDFversion=< 4.2.1

Published CVSS scores

8.1Red HatCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
9.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:L
6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A: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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo