CVE-2026-25731Public exploit

Code execution via unsandboxed template evaluation

Published Feb 6, 2026 · Updated Feb 6, 2026

Server-side template injection in Kovid Goyal calibre before 9.2.0 allows attackers to execute code through a malicious HTML export template. The HTML output plugin reads --template-html or --template-html-index files and passes their contents to Templite, which compiles generated Python and evaluates it without a sandbox. Execution requires a local user or automated pipeline to select the attacker-supplied template, and the payload runs with that process's privileges.

CVSS severity7.8
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Server-side template injection in Kovid Goyal calibre before 9.2.0 allows attackers to execute code through a malicious HTML export template. The HTML output plugin reads --template-html or --template-html-index files and passes their contents to Templite, which compiles generated Python and evaluates it without a sandbox. Execution requires a local user or automated pipeline to select the attacker-supplied template, and the payload runs with that process's privileges.

The record

CVE
CVE-2026-25731
Published
Feb 6, 2026
Updated
Feb 6, 2026
Vendor
Kovid Goyal
Product
calibre
Classifications
CWE-1336, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 6, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 9.2.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Kovid Goyal · calibreversion=< 9.2.0

Published CVSS scores

7.8GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-1336Improper Neutralization of Special Elements Used in a Template Engine
T1203Exploitation for Client Execution
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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