CVE-2026-28809

What it is

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.

At a glance

Exploitability

Can be exploited over the network without logging in. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-03-23 11:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-07-24 15:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.3% in the next 30 days (EPSS).
• Severity: 6.3 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-03-23 11:16 UTC

Last modified

2026-07-24 15:17 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-611 · XML external entity

Record status

Modified

Affected

• Arekinath Esaml ≤ 1.1
• Dropbox Esaml
• handnot2 Esaml ≤ 4.2.0
• jump-app Esaml ≤ 4.6.0

Attack profile CVSS 4.0 · 6.3

Attack vector

Network

Complexity

Low

Attack requirements

Present

Privileges needed

None

User interaction

None

Confidentiality

Low

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-28809.md and follow it. Check whether this project is affected by CVE-2026-28809. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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