CVE-2023-39318

Improper handling of HTML-like comments in script contexts in html/template

MEDIUM
6.1
CVSS Score
Published: September 8, 2023 at 04:13 PM UTC
Updated: June 17, 2026 at 06:12 AM UTC
2 products affected across 2 vendorsGoGo

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.9%
SSVC
No known exploit

Description

The html/template package does not properly handle HTML-like "" comment tokens, nor hashbang "#!" comment tokens, in <script> contexts. This may cause the template parser to improperly interpret the contents of <script> contexts, causing actions to be improperly escaped. This may be leveraged to perform an XSS attack.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.20.81.21.0 ≤ v < 1.21.1
Affected range stops below 1.20.8, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.21.1, so it looks safe — our inference, not a vendor statement
v < 1.20.81.21.0-0 ≤ v < 1.21.11.21.0-0
Affected range stops below 1.20.8, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.21.1, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-79

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