CVE-2024-56522: tecnickcom/tcpdf · TCPDF has incorrect comparison
Affects tecnickcom/tcpdfSource GCVE Database
Not known to be exploited · CVSS 7.5 High : upgrade to 6.8.0 soon.
Data as of 29 Oct 2026, 22:52 UTC
- Patch
- Available – fixed in 6.8.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NExploitation evidence
Disclosed: evidence found.
CVE published 27 Dec 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade tecnickcom/tcpdf to 6.8.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Packagisttecnickcom/tcpdf | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
An issue was discovered in TCPDF before 6.8.0. unserializeTCPDFtag uses != (aka loose comparison) and does not use a constant-time function to compare TCPDF tag hashes.
References
- nvd.nist.gov/vuln/detail/CVE-2024-56522 (opens in a new tab)
- github.com/tecnickcom/TCPDF/commit/d54b97cec33f4f1a5ad81119a82085cad93cec89 (opens in a new tab)
- github.com/tecnickcom/TCPDF (opens in a new tab)
- github.com/tecnickcom/TCPDF/compare/6.7.8...6.8.0 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2025/06/msg00004.html (opens in a new tab)
- tcpdf.org (opens in a new tab)
- php.net/manual/en/types.comparisons.php (opens in a new tab)