Description
An out-of-bounds write issue has been discovered in the backspace handling of the checkType() function in etc.c within the W3M application. This vulnerability is triggered by supplying a specially crafted HTML file to the w3m binary. Exploitation of this flaw could lead to application crashes, resulting in a denial of service condition.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | w3m | — | — |
| Fedora | Fedora | — | — |
| Fedora | Extra Packages for Enterprise Linux | — | — |
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+git20230121-2.1 | — |
| Debian 13 | w3m | 0.5.3+git20230121-2.1 | — |
| Debian 12 | w3m | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | w3m | 0.5.3+git20230121-2ubuntu1 | — |
| Ubuntu 22.04 LTS | w3m | 0.5.3+git20210102-6ubuntu0.2 | USN-6580-1 |
| Ubuntu 20.04 LTS | w3m | 0.5.3-37ubuntu0.2 | USN-6580-1 |
| Ubuntu 16.04 LTS | w3m | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | w3m | 0.5.3-36ubuntu0.1+esm1 | USN-6580-1 |
| Ubuntu Pro 14.04 LTS | w3m | 0.5.3-15ubuntu0.2+esm2 | USN-6580-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP5 | w3m | 0.5.3.git20161120-161.9.1 | SUSE-SU-2024:0014-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP5 | w3m | 0.5.3.git20161120-161.9.1 | SUSE-SU-2024:0014-1 |
Advisories 4
- USN-6580-1 w3m vulnerability Ubuntu Security Notices (USN) · Jun 29, 2026
- SUSE-SU-2024:0014-1 Security update for w3m SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2024-3377 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 12, 2025
- WID-SEC-2024-0004 w3m: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Mar 18, 2024
References
- RHBZ#2255207 issue-tracking
- https://github.com/tats/w3m/commit/edc602651c506aeeb60544b55534dd1722a340d3
- https://github.com/tats/w3m/issues/268
- https://github.com/tats/w3m/pull/273
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AULOBQJLXE2KCT5UVQMKGEFL4GFIAOED/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/TODROGVCWZ435HQIZE6ARQC5LPQLIA5C/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/MKFZQUK7FPWWJQYICDZZ4YWIPUPQ2D3R/