CVE-2005-4839: PureTLS before 0.9b5 does not clear optional Extensions and Algorithm.Parameters values before parsing, which

Q: How do I fix CVE-2005-4839?

puretls: upgrade to newer than 0.9b4. Exact commands for each OS are on this page.

Q: Is CVE-2005-4839 being exploited?

CVE-2005-4839 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2005-4839 affect?

CVE-2005-4839 affects puretls. Severity is medium (CVSS 5.0). PureTLS before 0.9b5 does not clear optional Extensions and Algorithm.Parameters values before parsing, which might trigger an information leak of values from earlier certificates.

Q: How urgent is CVE-2005-4839?

Priority 29/100. No elevated risk signals yet.

Routine

MEDIUM 5.0UPGRADE

CVE-2005-4839 is a medium-severity flaw (CVSS 5.0) affecting puretls. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

PureTLS before 0.9b5 does not clear optional Extensions and Algorithm.Parameters values before parsing, which might trigger an information leak of values from earlier certificates.

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	5.0 (Medium)
EPSS exploit chance	0.5% (top 54%)
CISA exploited list	No
Published	2005-12-31
Last modified	2026-06-16

Publisher (CNA): Red Hat, Inc. · Vendor: claymore systems inc

Last updated 2026-06-16 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2005-12-31 05:00 UTCPublished CVE record published
2026-06-16 22:19 UTCUpdated Record last modified

claymore systems inc puretls UPGRADE

Affected: <= 0.9b4

Fixed in: newer than 0.9b4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy puretls || rpm -q puretls || puretls --version

2. UPGRADE to newer than 0.9b4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade puretls

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade puretls

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2005-4839?

puretls: upgrade to newer than 0.9b4. Exact commands for each OS are on this page.

Is CVE-2005-4839 being exploited?

CVE-2005-4839 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-2005-4839 affect?

CVE-2005-4839 affects puretls. Severity is medium (CVSS 5.0). PureTLS before 0.9b5 does not clear optional Extensions and Algorithm.Parameters values before parsing, which might trigger an information leak of values from earlier certificates.

How urgent is CVE-2005-4839?

Priority 29/100. No elevated risk signals yet.

Related CVEs

CVE-2002-0420 HIGH 7.5 DOWNGRADE Vulnerability in PureTLS before 0.9b2 related to injection attacks, which could possibly allow remote attacker

References

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