Description
Let's Encrypt client and ACME library written in Go (Lego). Prior to 4.34.0, the webroot HTTP-01 challenge provider in lego is vulnerable to arbitrary file write and deletion via path traversal. A malicious ACME server can supply a crafted challenge token containing ../ sequences, causing lego to write attacker-influenced content to any path writable by the lego process. This vulnerability is fixed in 4.34.0.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| go-acme | lego | < 4.34.0 | — |
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 | golang-github-xenolf-lego | 4.35.2-1 | — |
| Debian 13 | golang-github-xenolf-lego | No fix yet | — |
| Debian 12 | golang-github-xenolf-lego | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | golang-github-xenolf-lego | No fix yet | — |
| Ubuntu 26.04 LTS | golang-github-xenolf-lego | No fix yet | — |
| Ubuntu 25.10 | golang-github-xenolf-lego | No fix yet | — |
| Ubuntu 22.04 LTS | golang-github-xenolf-lego | No fix yet | — |
| Ubuntu 20.04 LTS | golang-github-xenolf-lego | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | golang-github-xenolf-lego | No fix yet | — |
| Ubuntu Pro 24.04 LTS | golang-github-xenolf-lego | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1 |
| SLES 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | SUSE-SU-2026:23227-1, SUSE-SU-2026:23216-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260727T201416-160000.1.1 | openSUSE-SU-2026:21551-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | sftpgo | 2.7.1-r8 | — |
| Wolfi rolling | traefik-3.6 | 3.6.13-r2 | — |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Go | github.com/go-acme/lego | <= 2.7.2 | — | GHSA-qqx8-2xmm-jrv8 |
| Go | github.com/go-acme/lego/v3 | <= 3.9.0 | — | GHSA-qqx8-2xmm-jrv8 |
| Go | github.com/go-acme/lego/v4 | < 4.34.0 | 4.34.0 | GHSA-qqx8-2xmm-jrv8 |
Advisories 3
- SUSE-SU-2026:23227-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 27, 2026
- SUSE-SU-2026:23216-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 27, 2026
- openSUSE-SU-2026:21551-1 Security update for govulncheck-vulndb SUSE / openSUSE Security Updates · Aug 12, 2026