XML External Entity (XXE) vulnerability in esaml (and its forks) allows an attacker to cause the system to read local files and incorporate their contents into processed SAML documents, and potentially perform SSRF via crafted SAML messages.
esaml parses attacker-controlled SAML messages using xmerl_scan:string/2 before signature verification without disabling XML entity expansion. On Erlang/OTP versions before 27, Xmerl allows entities by default, enabling pre-signature XXE attacks. An attacker can cause the host to read local files (e.g., Kubernetes-mounted secrets) into the SAML document. If the attacker is not a trusted SAML SP, signature verification will fail and the document is discarded, but file contents may still be exposed through logs or error messages.
This issue affects all versions of esaml, including forks by arekinath, handnot2, and dropbox. Users running on Erlang/OTP 27 or later are not affected due to Xmerl defaulting to entities disabled.
References
| Link | Resource |
|---|---|
| https://cna.erlef.org/cves/CVE-2026-28809.html | Third Party Advisory Patch |
| https://github.com/Jump-App/esaml/commit/bab85efde7c136911402a881ca55173759467a26 | Patch |
| https://osv.dev/vulnerability/EEF-CVE-2026-28809 | Third Party Advisory |
Configurations
Configuration 1 (hide)
|
History
22 May 2026, 15:09
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.3 |
| CPE | cpe:2.3:a:dropbox:esaml:-:*:*:*:*:*:*:* cpe:2.3:a:arekinath:esaml:*:*:*:*:*:*:*:* cpe:2.3:a:handnot2:esaml:*:*:*:*:*:*:*:* cpe:2.3:a:jump-app:esaml:*:*:*:*:*:*:*:* |
|
| References | () https://cna.erlef.org/cves/CVE-2026-28809.html - Third Party Advisory, Patch | |
| References | () https://github.com/Jump-App/esaml/commit/bab85efde7c136911402a881ca55173759467a26 - Patch | |
| References | () https://osv.dev/vulnerability/EEF-CVE-2026-28809 - Third Party Advisory | |
| First Time |
Handnot2
Handnot2 esaml Dropbox Jump-app Jump-app esaml Dropbox esaml Arekinath Arekinath esaml |
06 Apr 2026, 17:17
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
|
| Summary |
|
23 Mar 2026, 11:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-03-23 11:16
Updated : 2026-05-22 15:09
NVD link : CVE-2026-28809
Mitre link : CVE-2026-28809
CVE.ORG link : CVE-2026-28809
JSON object : View
Products Affected
handnot2
- esaml
dropbox
- esaml
arekinath
- esaml
jump-app
- esaml
CWE
CWE-611
Improper Restriction of XML External Entity Reference
