# CVE-2026-75818: GNU Aspell prezip-bin heap buffer overflow in decompressor

Source: https://junglewise.ai/threats/cve-2026-75818-gnu-aspell-prezip-bin-contains-a-heap-based-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-75818 · Severity: info · Published 2026-10-06

GNU Aspell is a free spell checker used by many applications and command-line tools. A heap buffer overflow in the prezip-bin decompressor allows an attacker to crash the application or potentially corrupt memory by providing a malicious compressed dictionary file. Users who process untrusted compressed files with prezip-bin face risk of denial of service or data corruption.

Technologies: [Gnu Aspell](https://junglewise.ai/threats/technologies/aspell). Vendors: [Gnu](https://junglewise.ai/threats/vendors/gnu).

## Quick answers

**Is CVE-2026-75818 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-75818 being exploited in the wild.

**How severe is CVE-2026-75818?** Informational severity, published 6 October 2026.

**Which products and versions are affected?** Gnu Aspell all before 0.60.8.3.

**Is there a fix for CVE-2026-75818?** Yes: fixed in 0.60.8.3. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-75818 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-75818?** Check whether you run Gnu Aspell at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.60.8.3

## Technical details

The decompressor in prog/prezip.c fails to validate buffer bounds before reading and writing compressed data, leading to out-of-bounds heap access. An attacker crafts a compressed file with invalid size fields that trigger the overflow when processed by prezip-bin. This results in memory corruption and application crash; exploitation requires user interaction (processing the malicious file).

## Affected products

- GNU Aspell all before 0.60.8.3

## Timeline

- 2026-10-06: disclosed
- 2026-10-06: patched: Fix committed; version 0.60.8.3 release pending

## References

- [http://aspell.net/](http://aspell.net/)
- [https://cert.pl/en/posts/2026/10/CVE-2026-75818](https://cert.pl/en/posts/2026/10/CVE-2026-75818)

## Related threats

- [GNU Aspell heap buffer overflow in dictionary loader](https://junglewise.ai/threats/cve-2026-103658-gnu-aspell-0-60-8-2-first-vulnerable-version-is-not-known)
- [GNU Aspell integer truncation in WritableDict::add()](https://junglewise.ai/threats/cve-2026-75820-gnu-aspell-contains-an-integer-truncation-vulnerability-in-the)
- [GNU Aspell out-of-bounds read in dictionary loading](https://junglewise.ai/threats/cve-2026-75819-gnu-aspell-contains-an-out-of-bounds-read-vulnerability-in)