CVE-2026-103658: GNU Aspell 0.60.8.2 (first vulnerable version is not known) contains a heap-based buffer overflow write (CWE-122) in…

Is it exploited?

Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of 29 Oct 2026. If CISA adds it, this page shows it as known exploited.

How likely is exploitation in the next 30 days?

0.2%

EPSS score, percentile 11.7 of all scored records. A probability estimated by FIRST, not a report of exploitation.

CISA's SSVC assessment in the CVE record lists exploitation as poc.

How severe?

5.9 Medium

CVSS v3.1 base score, given by the CNA

What should I do?

CISA has set no required action, because the vulnerability is not in KEV.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• 0.60.8.2

Versions by product

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026; CVE List, as of 29 Oct 2026. About the data.

What to do

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

This summary is based on the CVE record as of 29 Oct 2026. Check the vendor's advisory before you act: affected versions and fixes can change.

Affected products and versions

As listed in the CVE record.

Source: CVE List, as of 29 Oct 2026. About the data.

About this vulnerability

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.cp…

Summary: CVE record, as of 29 Oct 2026.

• CISA has not added CVE-2026-103658 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
• The CVE record was published on 12 Oct 2026.
• The CVE record carries a CVSS v3.1 base score of 5.9 (Medium), given by its CNA.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.2% (percentile 11.7), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
• CISA's SSVC assessment in the CVE record: exploitation poc, automatable no, technical impact partial.
• The credits in the CVE record name Anthropic (Claude) as finder.

Source: CISA KEV 2026.10.29, as of 29 Oct 2026; CVE List, as of 29 Oct 2026; FIRST EPSS, as of 29 Oct 2026. About the data.

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.

Source: CVE List, as of 29 Oct 2026. About the data.

Timeline

Known exploited GNU vulnerabilities

• CVE-2026-24061: GNU InetUtils Argument Injection Vulnerability (added 26 Jan 2026)
• CVE-2014-6278: GNU Bash OS Command Injection Vulnerability (added 2 Oct 2025)
• CVE-2023-4911: GNU C Library Buffer Overflow Vulnerability (added 21 Nov 2023)
• CVE-2014-6271: GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability (added 28 Jan 2022)
• CVE-2014-7169: GNU Bourne-Again Shell (Bash) Arbitrary Code Execution Vulnerability (added 28 Jan 2022)