CVE-2026-25635: kovidgoyal calibre · Path Traversal
Affects kovidgoyal calibreSource CVE Database V5
Not known to be exploited · CVSS 8.6 High : upgrade to 9.2.0 soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 9.2.0
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade calibre and kovidgoyal/calibre to 9.2.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| kovidgoyalcalibre | Affected
| Fixed in
|
GitHubkovidgoyal/calibrepkg:github/kovidgoyal/calibreOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
European organizations should immediately upgrade all calibre installations to version 9.2.0 or later to remediate this vulnerability. Until upgrades can be performed, organizations should implement strict controls on the handling of CHM files, including blocking or quarantining CHM attachments in email gateways and endpoint security solutions. User education campaigns should emphasize the risks of opening untrusted CHM files and encourage caution with unknown e-book sources. Endpoint detection and response (EDR) tools should be configured to monitor and alert on suspicious file writes to startup folders or unusual process executions triggered by calibre. Application whitelisting can prevent unauthorized executables from running at startup. Network segmentation and least privilege principles should be enforced to limit the impact of potential compromises. Regular vulnerability scanning and patch management processes should be enhanced to ensure timely updates of calibre and other software. Finally, incident response plans should be updated to include detection and remediation steps for exploitation attempts involving this vulnerability.
Description
calibre is an e-book manager. Prior to 9.2.0, Calibre's CHM reader contains a path traversal vulnerability that allows arbitrary file writes anywhere the user has write permissions. On Windows (haven't tested on other OS's), this can lead to Remote Code Execution by writing a payload to the Startup folder, which executes on next login. This vulnerability is fixed in 9.2.0.