CVE-2024-56522

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.

Published: 2024-12-27 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-56522 is rated Moderate Risk (45.5/100): CVSS High severity, with low exploitation likelihood (EPSS 0.58%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2024-56522

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.15% 0.58% +0.43%
2 2026-05-18 0.10% 0.15% +0.06%
3 2026-02-04 — 0.10% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-56522

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-56522

GitHub Security Advisory for CVE-2024-56522

GHSA-w95c-7994-ghpr · Severity: high · Ecosystem: composer — TCPDF has incorrect comparison

OS Trackers for CVE-2024-56522

vendor priority summary link
debian not yet assigned CVE-2024-56522 not yet assigned priority: Debian including 1 source packages (tcpdf), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2024-56522
ubuntu medium CVE-2024-56522 medium priority: Ubuntu including 1 source packages (tcpdf), 10 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): needs-triage 6, not-affected 2, ignored 1, released 1. https://ubuntu.com/security/CVE-2024-56522

Affected software / configurations for CVE-2024-56522

Vendor Product Version Raw CPE
tcpdf_project tcpdf < 6.8.0 cpe:2.3:a:tcpdf_project:tcpdf:*:*:*:*:*:*:*:*

References for CVE-2024-56522

cvelogic Threat Intelligence