XML comment injection in Saxy encoder via unescaped double hyphen
- Exploited
- No known exploitation
- Fix
- Fixed in 1.7.0
- Who is exposed
- Not reported
Do first: Upgrade to a fixed version: 1.7.0.
- Last modified
- A 0-100 score for how much a CVE matters across the industry: exploitation, exposure, how widely the software is used, severity and whether a fix exists.What do these mean? →
- 12/100 · provisional
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
Saxy, an Elixir XML library, does not escape the `--` sequence or a closing `-->` in comment content, so a local attacker who can supply text that an application writes as a comment can inject arbitrary markup into the serialized document, without logging in and without any user action. Downstream parsers may then read forged elements, attributes, or text, which becomes cross-site scripting when the output is rendered as HTML or SVG.
Written by anthropic/claude-haiku-5.5 from the sources below. Verify against them.
Read the original 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.
cve.now Index
- Exploitation?/40Unknown. No CISA SSVC exploitation rating yet
- Exposure?/25Unknown. No advisory context yet
- Reach10/20Affects Hex packages
- Severity2.1/10CVSS 2.1
- No patch0/5No signal
What would change the score
- Would score about 67 if added to CISA KEV
- Would score about 62 if CISA's SSVC rates exploitation active
- Would score about 34 if advisories confirm default setups are exposed
What to do
Upgrade to a fixed version: 1.7.0.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- saxyHex
From 0.7.0 · fixed in 1.7.0
- qcam/saxy
Version range not reported
- saxyHex
From 0.7.0 · fixed in 1.7.0
Evidence 5
- Advisory
- Patch
- Repository
- Link
- Link
Corrections
None so far.
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Questions about CVE-2026-66293
Is CVE-2026-66293 being exploited?
It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.Source: cve.now feed data
Which versions are affected by CVE-2026-66293?
saxy (Hex): from 0.7.0 before 1.7.0. saxy (Hex): from 0.7.0 before 1.7.0.Source: cve.now feed data
How do I fix CVE-2026-66293?
Upgrade to a fixed version: 1.7.0.Source: cve.now feed data