CVE-2024-56521: An issue was discovered in TCPDF before 6.8.0

Q: How do I fix CVE-2024-56521?

tcpdf: upgrade to 6.8.0. Exact commands for each OS are on this page.

Q: Is CVE-2024-56521 being exploited?

CVE-2024-56521 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-2024-56521 affect?

CVE-2024-56521 affects tcpdf. Severity is critical (CVSS 9.8). An issue was discovered in TCPDF before 6.8.0. If libcurl is used, CURLOPT_SSL_VERIFYHOST and CURLOPT_SSL_VERIFYPEER are set unsafely.

Q: How urgent is CVE-2024-56521?

Priority 53/100. Critical severity; Remotely exploitable, no login, no user action

This month

CRITICAL 9.8REMOTEUPGRADE

CVE-2024-56521 is a critical-severity flaw (CVSS 9.8) affecting tcpdf. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in TCPDF before 6.8.0. If libcurl is used, CURLOPT_SSL_VERIFYHOST and CURLOPT_SSL_VERIFYPEER are set unsafely.

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.8 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 44%)
CISA exploited list	No
Weakness	CWE-295
Published	2024-12-27
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: tcpdf project

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

Am I affected?

Timeline

2024-12-27 05:15 UTCPublished CVE record published
2026-06-17 08:12 UTCUpdated Record last modified

tcpdf project tcpdf UPGRADE

Affected: < 6.8.0

Fixed in: 6.8.0

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 6.8.0 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tcpdf

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-2024-56521?

tcpdf: upgrade to 6.8.0. Exact commands for each OS are on this page.

Is CVE-2024-56521 being exploited?

CVE-2024-56521 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-2024-56521 affect?

CVE-2024-56521 affects tcpdf. Severity is critical (CVSS 9.8). An issue was discovered in TCPDF before 6.8.0. If libcurl is used, CURLOPT_SSL_VERIFYHOST and CURLOPT_SSL_VERIFYPEER are set unsafely.

How urgent is CVE-2024-56521?

Priority 53/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

curl vulnerabilities

Related CVEs

CVE-2024-56527 HIGH 7.5 UPGRADE An issue was discovered in TCPDF before 6.8.0
CVE-2024-56522 HIGH 7.5 UPGRADE An issue was discovered in TCPDF before 6.8.0
CVE-2024-56519 HIGH 7.5 UPGRADE An issue was discovered in TCPDF before 6.8.0
CVE-2024-51058 MEDIUM 6.2 DOWNGRADE Local File Inclusion (LFI) vulnerability has been discovered in TCPDF 6.7.5

References

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