Description
An issue was discovered in the Tatsuya Kinoshita w3m fork before 0.5.3-31. Buffer overflow in the formUpdateBuffer function in w3m allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via a crafted HTML page.
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 | w3m | 0.5.3-30 | — |
| Debian 13 | w3m | 0.5.3-30 | — |
| Debian 12 | w3m | 0.5.3-30 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | w3m | 0.5.3-26ubuntu0.1 | — |
| Ubuntu 14.04 LTS | w3m | 0.5.3-15ubuntu0.1 | USN-3214-1 |
Advisories 1
- USN-3214-1 w3m vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026