kovidgoyal calibre up to 9.1.x Templite Templating Engine special elements used in a template engine

CVSS Meta Temp Score
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CTI Interest Score
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6.9$0-$5k0.00

Summaryinfo

A vulnerability was found in kovidgoyal calibre up to 9.1.x. It has been rated as critical. The affected element is an unknown function of the component Templite Templating Engine. Performing a manipulation results in improper neutralization of special elements used in a template engine. This vulnerability is reported as CVE-2026-25731. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in kovidgoyal calibre up to 9.1.x. This affects an unknown function of the component Templite Templating Engine. The manipulation with an unknown input leads to a improper neutralization of special elements used in a template engine vulnerability. CWE is classifying the issue as CWE-1336. The product uses a template engine to insert or process externally-influenced input, but it does not neutralize or incorrectly neutralizes special elements or syntax that can be interpreted as template expressions or other code directives when processed by the engine. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

calibre is an e-book manager. Prior to 9.2.0, a Server-Side Template Injection (SSTI) vulnerability in Calibre's Templite templating engine allows arbitrary code execution when a user converts an ebook using a malicious custom template file via the --template-html or --template-html-index command-line options. This vulnerability is fixed in 9.2.0.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-25731 since 02/05/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1221 for this issue.

The vulnerability scanner Nessus provides a plugin with the ID 298306 (Linux Distros Unpatched Vulnerability : CVE-2026-25731), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 9.2.0 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (298306) and EUVD (EUVD-2026-5573). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Vendor

Name

Version

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.0
VulDB Meta Temp Score: 6.9

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (GitHub_M): 🔒

CVSSv2info

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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper neutralization of special elements used in a template engine
CWE: CWE-1336 / CWE-791 / CWE-790
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298306
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2026-25731

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: calibre 9.2.0

Timelineinfo

02/05/2026 CVE reserved
02/06/2026 +1 days Advisory disclosed
02/06/2026 +0 days VulDB entry created
02/18/2026 +12 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-25731 (🔒)
GCVE (CVE): GCVE-0-2026-25731
GCVE (VulDB): GCVE-100-344757
EUVD: 🔒

Entryinfo

Created: 02/06/2026 21:41
Updated: 02/18/2026 02:23
Changes: 02/06/2026 21:41 (63), 02/07/2026 06:41 (1), 02/08/2026 00:36 (2), 02/18/2026 02:23 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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