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.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | mupdf | 1.27.0+ds1-2 | — |
| Debian 13 | mupdf | No fix yet | — |
| Debian 12 | mupdf | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | mupdf | No fix yet | — |
| Ubuntu 26.04 LTS | mupdf | No fix yet | — |
| Ubuntu 25.10 | mupdf | No fix yet | — |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | mupdf | No fix yet | — |
| Ubuntu Pro 22.04 LTS | mupdf | No fix yet | — |
| Ubuntu Pro 20.04 LTS | mupdf | No fix yet | — |
| Ubuntu Pro 18.04 LTS | mupdf | No fix yet | — |
| Ubuntu Pro 16.04 LTS | mupdf | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | mupdf | 1.27.1-1.1 | openSUSE-SU-2026:10214-1 |
| openSUSE Leap 16.0 | mupdf | 1.27.2-bp160.1.1 | openSUSE-SU-2026:21180-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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ISH2YU/CVE-2025-55780 ★ 0 · Sep 24, 2025
Null Pointer Dereference in MuPDF , First CVE discovered by me
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 2
- openSUSE-SU-2026:21180-1 Security update for mupdf SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:10214-1 mupdf-1.27.1-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026