Vulnerability · Published Oct 12, 2026 · Assigned by Anthropic
CVE-2026-103658
Medium 5.9
In plain English
A medium-severity heap buffer overflow in Aspell from GNU. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
GNU Aspell 0.60.8.2 (first vulnerable version is not known) contains a heap-based buffer overflow write (CWE-122) in its read-only dictionary loader. String::reserve() in common/string.hpp computes its capacity check with a signed int ((int)s + 1), so a requested size of 0x7FFFFFFF wraps negative and the backing buffer is never grown. ReadOnlyDict::load() in modules/speller/default/readonly_ws.cpp passes the unvalidated 32-bit size fields from a .rws dictionary header into this path, so a crafted .rws file with a valid endian marker (12345678) and an oversized length field (e.g. lang_name_size = 0x7FFFFFFF) causes attacker-controlled data to be written out of bounds past an undersized heap allocation. An attacker who induces a victim to load a malicious dictionary — for example via aspell dump master <file> — can corrupt heap memory, resulting in denial of service and potentially code execution. Fixed in b830b6e and will be fixed in release 0.60.8.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | aspell | 12:0.60.6.1-23.el8_10 | ALSA-2026:92615 |
| AlmaLinux:9 | aspell | 12:0.60.8-9.el9_8 | ALSA-2026:92458 |
| AlmaLinux:8 | aspell-devel | 12:0.60.6.1-23.el8_10 | ALSA-2026:92615 |
| AlmaLinux:9 | aspell-devel | 12:0.60.8-9.el9_8 | ALSA-2026:92458 |
| Debian:12 | aspell | no fix listed | DEBIAN-CVE-2026-103658 |
| Debian:13 | aspell | no fix listed | DEBIAN-CVE-2026-103658 |
| Debian:14 | aspell | 0.60.8.2-4 | DEBIAN-CVE-2026-103658 |
| Rocky Linux:8 | aspell | 2:0.60.6.1-23.el8_10 | RLSA-2026:92615 |
| Rocky Linux:9 | aspell | 2:0.60.8-9.el9_8 | RLSA-2026:92458 |
| Ubuntu:22.04:LTS | aspell | no fix listed | UBUNTU-CVE-2026-103658 |
| Ubuntu:24.04:LTS | aspell | no fix listed | UBUNTU-CVE-2026-103658 |
| Ubuntu:26.04:LTS | aspell | no fix listed | UBUNTU-CVE-2026-103658 |
| Ubuntu:26.10 | aspell | no fix listed | UBUNTU-CVE-2026-103658 |
Affected products (as reported)
Weakness: CWE-122 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L