# TCPDF has incorrect comparison

Advisory record · `GHSA-w95c-7994-ghpr`

- **Identifiers:** `GHSA-w95c-7994-ghpr` · `CVE-2024-56522` · `PKSA-wb9y-hg45-chz4`
- **State:** Confirmed
- **Severity:** CVSS 7.5 High
- **Critical:** No
- **Weakness (CWE):** [CWE-697](https://cwe.mitre.org/data/definitions/697.html) · [CWE-843](https://cwe.mitre.org/data/definitions/843.html)
- **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) · [CWE-697](https://agentprime.io/advisories/tag/cwe-697.md)
- **Published:** 27 Dec 2024
- **Updated:** 3 Nov 2025
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 27 Dec 2024, 06:30 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `tecnickcom/tcpdf` (Packagist): affected `<6.8.0`; fixed in `6.8.0`

## Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

> TCPDF versions before 6.8.0 (tecnickcom/tcpdf) use a loose comparison and a non-constant-time function when checking TCPDF tag hashes in unserializeTCPDFtag. The source gives few details on how an attacker would exploit this or what impact results. Upgrade tecnickcom/tcpdf to 6.8.0 or later.

Written 3 Nov 2026.

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 7.5 High, CVSS 3.1: `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`, from GitHub Advisory Database

- **CISA KEV:** Not listed.
- **EPSS:** 0.0061, the 49th percentile, on 6 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:26 UTC: First seen by agentprime
- 31 Oct 2026, 14:26 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-w95c-7994-ghpr)

## Sources

- [GitHub Advisory Database: GHSA-w95c-7994-ghpr](https://github.com/advisories/GHSA-w95c-7994-ghpr)
- [OSV: GHSA-w95c-7994-ghpr](https://osv.dev/vulnerability/GHSA-w95c-7994-ghpr)
- <https://nvd.nist.gov/vuln/detail/CVE-2024-56522>
- <https://github.com/tecnickcom/TCPDF/commit/d54b97cec33f4f1a5ad81119a82085cad93cec89>
- <https://github.com/tecnickcom/TCPDF>
- <https://github.com/tecnickcom/TCPDF/compare/6.7.8...6.8.0>
- <https://lists.debian.org/debian-lts-announce/2025/06/msg00004.html>
- <https://tcpdf.org/>
- <https://www.php.net/manual/en/types.comparisons.php>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-w95c-7994-ghpr>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-w95c-7994-ghpr/>. Everything for agents: <https://agentprime.io/llms.txt>.