CVE-2026-28809

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.

CVSS v3 5.3 MEDIUM

5.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 3.9 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact LOW

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cna.erlef.org/cves/CVE-2026-28809.html	Patch Third Party Advisory
https://github.com/Jump-App/esaml/commit/bab85efde7c136911402a881ca55173759467a26	Patch
https://osv.dev/vulnerability/EEF-CVE-2026-28809	Third Party Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:arekinath:esaml::::::::
	cpe:2.3:a:dropbox:esaml:-:::::::*
	cpe:2.3:a:handnot2:esaml::::::::
	cpe:2.3:a:jump-app:esaml::::::::

History

No history.

Information

Published : 2026-03-23 11:16

Updated : 2026-07-24 15:17

NVD link : CVE-2026-28809

Mitre link : CVE-2026-28809

CVE.ORG link : CVE-2026-28809

JSON object : View

Products Affected

jump-app

esaml

handnot2

esaml

dropbox

esaml

arekinath

esaml

CWE

CWE-611

Improper Restriction of XML External Entity Reference

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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.\n\nesaml parses attacker-controlled SAML messages using xmerl_scan:string/2 before signature verification without disabling XML entity expansion. 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Los usuarios que ejecutan Erlang/OTP 27 o posterior no se ven afectados debido a que Xmerl deshabilita las entidades por defecto."}], "lastModified": "2026-07-24T15:17:15.077", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:arekinath:esaml:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "632ECB93-A90B-4407-8BAB-433D2A363B7E", "versionEndIncluding": "1.1"}, {"criteria": "cpe:2.3:a:dropbox:esaml:-:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "0392F7E9-6EBE-49F6-B54D-C8539A6A0F9E"}, {"criteria": "cpe:2.3:a:handnot2:esaml:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1F58CE0D-4684-452D-8A61-ACC5DB13BE2A", "versionEndIncluding": "4.2.0"}, {"criteria": "cpe:2.3:a:jump-app:esaml:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7BA5EFB0-D3E0-4900-A14F-B5E08135224F", "versionEndIncluding": "4.6.0"}], "operator": "OR"}]}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}