XML External Entity (XXE) vulnerability in Square Retrofit

published 2018-12-20 7 y ago modified 2026-06-17 4 mo ago also GHSA-j379-9jr9-w5cq , EUVD-2018-0813

cvss: 9.1; version 3.0, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 2.2%; EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits: 0; none known

Square Open Source Retrofit version Prior to commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437 contains a XML External Entity (XXE) vulnerability in JAXB that can result in An attacker could use this to remotely read files from the file system or to perform SSRF.. This vulnerability appears to have been fixed in After commit 4a693c5aeeef2be6c7ecf80e7b5ec79f6ab59437.

Patch / fix

fixed in 2 links 1

maven com.squareup.retrofit2:retrofit 2.5.0
squareup retrofit 2.5.0

github.com/square/retrofit#2735 pull request

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-1000844 updated 2026-08-04 cvss 6.5

retrofit: XML external entity processing vulnerability in JAXB

Red Hat Fuse 7 retrofit
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.15% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.0	9.1	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
NVD	2.0	6.4	AV:N/AC:L/Au:N/C:P/I:P/A:N
GitHub	3.0	9.1	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	com.squareup.retrofit2:retrofit	>=2.0.0, <2.5.0	2.5.0

Classification

Weakness

CWE-611 Improper Restriction of XML External Entity Reference

References

github.com /square/retrofit/pull/2735
web, third-party-advisory
nvd.nist.gov /vuln/detail/CVE-2018-1000844
advisory
github.com /advisories/GHSA-j379-9jr9-w5cq
advisory
github.com /square/retrofit
package

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary