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Fencer Vulns
high 7.5

CVE-2024-56522 json

TCPDF has incorrect comparison

published 2024-12-27 22 mo ago modified 2026-06-17 4 mo ago also GHSA-w95c-7994-ghpr , EUVD-2024-3618

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits
0
none known

Summary

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.

Patch / fix

  • packagist tecnickcom/tcpdf 6.8.0
  • tecnick tcpdf 6.8.0
  • tcpdf Debian 12 6.6.2+dfsg1-1+deb12u1
  • tcpdf Debian 14, Debian 13 6.8.0+dfsg-1

debian advisories DEBIAN-CVE-2024-56522

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2024-56522 updated

TCPDF: unserializeTCPDFtag uses != (aka loose comparison) and does not use a constant-time function to compare TCPDF tag hashes

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
22 mo ago

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
packagist tecnickcom/tcpdf
<6.8.0
6.8.0

Affected products

  • tecnick tcpdf

Classification

Weakness
  • CWE-843 Access of Resource Using Incompatible Type
  • CWE-697 Incorrect Comparison

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.