CVE-2021-37819: PDF Labs pdftk-java v3.2.3 was discovered to contain an infinite loop via the component /text/pdf/PdfReader.ja

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HIGH 7.5REMOTEDOWNGRADE

CVE-2021-37819 is a high-severity flaw (CVSS 7.5) affecting pdftk-java. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PDF Labs pdftk-java v3.2.3 was discovered to contain an infinite loop via the component /text/pdf/PdfReader.java.

Why this priority

High severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 42%)
CISA exploited list	No
Weakness	CWE-835
Published	2022-09-09
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: pdftk-java project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-09-09 22:15 UTCPublished CVE record published
2026-06-17 04:01 UTCUpdated Record last modified

pdftk-java project pdftk-java DOWNGRADE

Affected: 3.2.3

Fixed in: no fixed release known

Safe to downgrade to: a release before 3.2.3

1. Check installed version

apt-cache policy pdftk-java || rpm -q pdftk-java || pdftk-java --version

2. No fixed release: DOWNGRADE to a release before 3.2.3 (Debian / Ubuntu)

apt-cache madison pdftk-java sudo apt install pdftk-java=<VERSION_BEFORE_3.2.3> sudo apt-mark hold pdftk-java

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list pdftk-java sudo dnf downgrade pdftk-java-<VERSION_BEFORE_3.2.3> sudo dnf versionlock add pdftk-java

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-37819?

pdftk-java: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-37819 being exploited?

CVE-2021-37819 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-37819 affect?

CVE-2021-37819 affects pdftk-java. Severity is high (CVSS 7.5). PDF Labs pdftk-java v3.2.3 was discovered to contain an infinite loop via the component /text/pdf/PdfReader.java.

How urgent is CVE-2021-37819?

Priority 46/100. High severity; Remotely exploitable, no login, no user action

Software pages

Java vulnerabilities

References

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