CVE-2026-66293

Published Nov 6, 2026 Modified Nov 10, 2026 CWE-91

Description

XML injection in the encoder of Saxy. Saxy.Encoder does not neutralize the -- sequence in XML comment content: escape_comment/2 returns the comment binary unchanged in every clause and only appends a space when the comment ends in a single -, so neither an interior -- nor a full --> is escaped or rejected before the encoder wraps the content in the <!-- and --> delimiters. When an application serializes attacker-controlled text as a comment, through Saxy.XML.comment/1 or a raw {:comment, text} simple form child, the attacker can close the comment early with --> and inject arbitrary sibling markup into the serialized document. A downstream parser then sees elements, attributes, and text that the application never built. Where the document is rendered as HTML or SVG, the injected markup executes as stored cross-site scripting; where it is consumed by another XML processor, the attacker can forge data that the producing application never emitted. Documents that Saxy only parses are not a vector. This issue affects saxy: from 0.7.0 before 1.7.0.

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EPSS — Exploit Prediction

0.0017
Probability of exploitation
0.06%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-91 CWE-91

References

Frequently Asked Questions

What is CVE-2026-66293? +
XML injection in the encoder of Saxy. Saxy.Encoder does not neutralize the -- sequence in XML comment content: escape_comment/2 returns the comment binary unchanged in every clause and only appends a space when the comment ends in a single -, so neither an interior -- nor a full --> is escaped or rejected before the encoder wraps the content in the <!-- and --> delimiters. When an application serializes attacker-controlled text as a comment, through Saxy.XML.comment/1 or a raw {:comment, text} simple form child, the attacker can close the comment early with --> and inject arbitrary sibling markup into the serialized document. A downstream parser then sees elements, attributes, and text that the application never built. Where the document is rendered as HTML or SVG, the injected markup executes as stored cross-site scripting; where it is consumed by another XML processor, the attacker can forge data that the producing application never emitted. Documents that Saxy only parses are not a vector. This issue affects saxy: from 0.7.0 before 1.7.0.
How do I check if I'm vulnerable to CVE-2026-66293? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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