CVE-2025-54799
Description
Let's Encrypt client and ACME library written in Go (Lego). In versions 4.25.1 and below, the github.com/go-acme/lego/v4/acme/api package (thus the lego library and the lego cli as well) don't enforce HTTPS when talking to CAs as an ACME client. Unlike the http-01 challenge which solves an ACME challenge over unencrypted HTTP, the ACME protocol requires HTTPS when a client communicates with the CA to performs ACME functions. However, the library fails to enforce HTTPS both in the original discover URL (configured by the library user) and in the subsequent addresses returned by the CAs in the directory and order objects. If users input HTTP URLs or CAs misconfigure endpoints, protocol operations occur over HTTP instead of HTTPS. This compromises privacy by exposing request/response details like account and request identifiers to network attackers. This was fixed in version 4.25.2.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Mitigation details
CVE-2025-54799 NameCVE-2025-54799 DescriptionLet's Encrypt client and ACME library written in Go (Lego). In versions 4.25.1 and below, the github.com/go-acme/lego/v4/acme/api package (thus the lego library and the lego cli as well) don't enforce HTTPS when talking to CAs as an ACME client. Unlike the http-01 challenge which solves an ACME challenge over unencrypted HTTP, the ACME protocol…
Workaround
CA endpoint should enforce HTTPS instead of HTTP.
CVE-2025-54799
| Name | CVE-2025-54799 |
| Description | Let's Encrypt client and ACME library written in Go (Lego). In versions 4.25.1 and below, the github.com/go-acme/lego/v4/acme/api package (thus the lego library and the lego cli as well) don't enforce HTTPS when talking to CAs as an ACME client. Unlike the http-01 challenge which solves an ACME challenge over unencrypted HTTP, the ACME protocol requires HTTPS when a client communicates with the CA to performs ACME functions. However, the library fails to enforce HTTPS both in the original discover URL (configured by the library user) and in the subsequent addresses returned by the CAs in the directory and order objects. If users input HTTP URLs or CAs misconfigure endpoints, protocol operations occur over HTTP instead of HTTPS. This compromises privacy by exposing request/response details like account and request identifiers to network attackers. This was fixed in version 4.25.2. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1110531 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|---|---|---|
| golang-github-xenolf-lego (PTS) | bullseye | 3.2.0-3.1 | vulnerable |
| bookworm | 4.9.1-1 | vulnerable | |
| trixie | 4.9.1-2 | vulnerable | |
| forky | 4.9.1-4 | vulnerable | |
| sid | 4.35.2-1 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|---|---|---|---|---|---|
| golang-github-xenolf-lego | source | (unstable) | 4.35.2-1 | 1110531 |
Notes
[trixie] - golang-github-xenolf-lego <no-dsa> (Minor issue)
[bookworm] - golang-github-xenolf-lego <no-dsa> (Minor issue)
[bullseye] - golang-github-xenolf-lego <ignored> (minor; need both client and server misconfigured unlikely)
https://github.com/go-acme/lego/security/advisories/GHSA-q82r-2j7m-9rv4
Fixed by: https://github.com/go-acme/lego/commit/238454b5f74f3cfcbb244ff0d0dc914a4ad44b96 (v4.25.2)
Workaround: CA endpoint should enforce HTTPS instead of HTTP.
Apply commands
[trixie] - golang-github-xenolf-lego <no-dsa> (Minor issue)[bookworm] - golang-github-xenolf-lego <no-dsa> (Minor issue)[bullseye] - golang-github-xenolf-lego <ignored> (minor; need both client and server misconfigured unlikely)https://github.com/go-acme/lego/security/advisories/GHSA-q82r-2j7m-9rv4Fixed by: https://github.com/go-acme/lego/commit/238454b5f74f3cfcbb244ff0d0dc914a4ad44b96 (v4.25.2)Workaround: CA endpoint should enforce HTTPS instead of HTTP.OS impact
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 4.35.2-1 |
| forky | Affected | — |
| bullseye | Affected | — |
| bookworm | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| Go | github.com/go-acme/lego | <=4.25.1 | |
| Go | github.com/go-acme/lego/v3 | <=4.25.1 | |
| Go | github.com/go-acme/lego/v4 | <4.25.2 | 4.25.2 |
References
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.