CVE-2025-55780 Null dereference in n/a
A null pointer dereference in MuPDF allows attackers to cause a denial of service via a malformed EPUB document.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-55780?
CVE-2025-55780 is a high-severity vulnerability in Artifex Mupdf, published on 23 Sep 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A null pointer dereference occurs in the function break_word_for_overflow_wrap() in MuPDF 1.26.4 when rendering a malformed EPUB document. Specifically, the function calls fz_html_split_flow() to split a FLOW_WORD node, but does not check if node->next is valid before accessing node->next->overflow_wrap, resulting in a crash if the split fails or returns a partial node chain.
Weakness: CWE-476
Which versions are affected by CVE-2025-55780?
It affects 1 product.
Products include Artifex Mupdf.
How do I fix CVE-2025-55780?
Apply the vendor's patch.
Is CVE-2025-55780 being exploited?
There is no known exploitation of CVE-2025-55780 in the wild and no public exploit code.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in Artifex Mupdf
Sources
Also known as DEBIAN-CVE-2025-55780, GHSA-756h-grq9-2jvh, UBUNTU-CVE-2025-55780.