Vulnerabilities in GNU Aspell software

CERT Polska has received a report about vulnerabilities in GNU Aspell software and participated in coordination of their disclosure.

The vulnerabilityCVE-2026-75818: GNU Aspellprezip-bincontains a heap-based buffer overflow vulnerability in the decompressor inprog/prezip.c. The decompressor does not properly check buffer space, so a crafted compressed file can cause out-of-bounds read and write operations on the heap. An attacker who convinces a user to process a malicious compressed file withprezip-bincan trigger memory corruption, leading to a processs crash.

This issue was fixed in commit 15b188437f9e0192d4ac4472ad66a4e2f62a782f which will be released in version 0.60.8.3.

The vulnerabilityCVE-2026-75819: GNU Aspell contains an out-of-bounds read vulnerability inReadOnlyDict::load()inreadonly_ws.cpp. When loading a binary.rwsdictionary file, it uses offset fields from the file header as byte indices into a heap buffer without validating their bounds. An attacker can trigger this by convincing a user to runaspellwith a crafted dictionary file supplied through--master,--dict-dir, or configuration options, leading to heap memory disclosure or a denial of service via application crash.

This issue was fixed in commit 941953b25031bc9104e83f58e138a664b8dedc3f which will be released in version 0.60.8.3.

The vulnerabilityCVE-2026-75820: GNU Aspell contains an integer truncation vulnerability in theWritableDict::add()function inmodules/speller/default/writable.cpp. When loading a personal wordlist, the word length is stored as a single byte, causing truncation for words whose length is a multiple of 256. This leads to heap corruption. An attacker can exploit this by convincing a user to runaspellwith a crafted personal wordlist containing such a word, resulting in denial of service.

This issue was fixed in commit 782ce94e4dc71eaec4ee1bd945eb3b9c47c5387d which will be released in version 0.60.8.3.

We thank Michał Majchrowicz and Marcin Wyczechowski from AFINE Team for the responsible vulnerability report.