CVE-2020-13965
An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. There is XSS via a malicious XML attachment because text/xml is among the allowed types for a preview.
- CVSS
- 6.1Medium
- Exploited in the wild
- Yes, in CISA KEV since 26 Jun 2024CISA deadline for US federal agencies: 17 Jul 2024unvetted proof-of-concept code on github
- EPSS
- 76.6%chance of exploitation in the next 30 daystop 0.5% of scored CVEsFIRST score of 11 Nov 2026
- Fix
- Patch availablesee the advisories in the references
- Published
- 9 Jun 2020analysed here 12 Nov 2026
Do first. Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. (CISA's required action for this KEV entry)
Summary
Triage
- Attack surface
- Client-side
- Exploitable
- At runtime
- Attack vector
- network
The summary, impact and action text on this page are written by our AI analysis pipeline, or taken from the NVD description when a CVE was imported from NVD. They are not the vendor's wording: check them against the sources. A longer AI executive summary and technical analysis are generated for signed-in accounts on the Max plan.
Affected products
Products named in our analysis
- roundcube:webmail
- debian:debian_linux
- fedoraproject:fedora
Fix and mitigation
WAF and other mitigations
Can a WAF block it? Yes. The attack involves sending a malicious XML attachment in an HTTP request to the webmail interface. A WAF could partially detect this by identifying unusual or suspicious XML attachments used for preview, but distinguishing malicious XML from legitimate XML attachments may be challenging. A custom WAF rule can filter HTTP request with a text/xml attachment for preview, but attackers can vary the request. No tracked WAF vendor has published a rule for this CVE yet.
What a custom rule would match: HTTP request with a text/xml attachment for preview
Also consider: patch · custom WAF rule · CSP · output encoding
Based on an AI reading of the CVE description, and no vendor rule found yet. We check Cloudflare, AWS, Google Cloud Armor and Azure; for Akamai, Imperva, Fastly, F5, ask your vendor.
Remediation steps (AI-written)
Step-by-step remediation is generated for accounts on the Max plan, for CVEs that match a technology in their stack. Add this technology to your stack to see the fix checklist.
Exploitation evidence
- CISA KEV catalog
- Listed since 26 Jun 2024.
- CISA due date
- 17 Jul 2024, the remediation deadline for US federal agencies
- CISA required action
- Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- Public exploit code
- Unvetted proof-of-concept code on GitHub: 1 GitHub proof of concept
- CISA SSVC
- exploitation active, automatable no, technical impact partialAssessed by CISA 26 Jun 2024 (SSVC 2.0.3). Exploitation is none, poc (public proof of concept) or active.
GitHub proofs of concept
- mbadanoiu/CVE-2020-139650 stars
Listed so you can judge urgency, not as a recommendation to run anything. GitHub “proofs of concept” are unvetted: some are fake or carry malware. Exploit-DB marks the entries its staff verified.
Timeline
- 9 Jun 2020Published
- 13 Apr 2024First proof-of-concept repository on GitHub (unvetted)1,404 days (about 4 years) later
- 26 Jun 2024Added to CISA KEV (exploited in the wild)74 days (about 2 months) later
- 26 Jun 2024CISA SSVC assessment: exploitation active1 day later
- 17 Jul 2024CISA remediation due date (US federal agencies)20 days later
- 21 Oct 2025CVE record last updated462 days (about 1 year) later
- 12 Nov 2026Analysed by vulneraibility.com387 days (about 1 year) later
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
| Metric | Value | What it means |
|---|---|---|
| Attack vector | NetworkReachable over the internet or any routable network. | Reachable over the internet or any routable network. |
| Attack complexity | LowRepeatable attack, no special conditions. | Repeatable attack, no special conditions. |
| Privileges required | NoneThe attacker needs no prior access. | The attacker needs no prior access. |
| User interaction | RequiredA victim must click, open or otherwise cooperate. | A victim must click, open or otherwise cooperate. |
| Scope | ChangedImpact crosses a security boundary into other components. | Impact crosses a security boundary into other components. |
| Confidentiality | LowPartial data disclosure. | Partial data disclosure. |
| Integrity | LowLimited modification possible. | Limited modification possible. |
| Availability | NoneThe service stays up. | The service stays up. |
Common questions
Is CVE-2020-13965 being exploited?
Yes. CVE-2020-13965 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2020-13965?
CVE-2020-13965 is rated Medium with a CVSS score of 6.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2020-13965?
Yes. A fix has been recorded for CVE-2020-13965. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2020-13965 affect?
CVE-2020-13965 affects roundcube:webmail, debian:debian_linux, fedoraproject:fedora. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
References
10 references in the CVE record, grouped by the tags the record gives them.
Advisories (3)
- debian.org /security/2020/dsa-4700
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/DLESQ4LPJGMSWH
- lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/ODPJXBHZ32QSP4
Other links (7)
- github.com /roundcube/roundcubemail/releases/tag/1.4.5
- github.com /roundcube/roundcubemail/releases/tag/1.3.12
- github.com /roundcube/roundcubemail/commit/884eb611627ef2bd5a2e20e02009ebb1eceecdc3
- github.com /roundcube/roundcubemail/compare/1.4.4...1.4.5
- roundcube.net /news/2020/06/02/security-updates-1.4.5-and-1.3.12
- github.com /DrunkenShells/Disclosures/tree/master/CVE-2020-13965-Cross%20Site-Scripting%20v
Show 1 more
- cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-13965
Where the data on this page comes from
- CVE List (CVE.org): description, affected versions, references; CVE Terms of Use
- NVD: CVSS and CPE data
- CISA KEV catalog: exploitation, date added, due date
- CISA Vulnrichment (ADP): SSVC decision points
- FIRST EPSS: exploit probability and percentile
- PoC-in-GitHub: GitHub repositories that claim a proof of concept
Summary, impact and triage tags: written by our AI analysis pipeline from the sources above. Check them against the sources.
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