CVE-2020-35730

mediumpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.329 · 98 %ileexploit · PoCDEEURUUS

grimoire priorityP0 · Act now

Exploitable?

Yes · in the wild

CISA KEV · 1 exploit · PoC

Likely / severe?

32.9% (98th) EPSS

CVSS 4.3 · medium

Is it mine?

19 products

Check your exposure

Who says so?

6 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

added 2023-06-22remediate by 2023-07-13

required action Apply updates per vendor instructions.

EPSS · scored 2026-10-26

Roundcube Webmail Cross-Site Scripting (XSS) Vulnerability

An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkref_addindex in rcube_string_replacer.php.

cvss

Technical severity, 0–10. One row per scoring source.

6.1

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.04.3mediumAV:N/AC:M/Au:N/C:N/I:P/A:Nprimary · NVD / NIST USexploitability 8.6 · impact 2.9

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 2.7

v3.16.1mediumAV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondary · ENISA EU

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:Nsecondaryexploitability 2.8 · impact 2.7

v3.16.1mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:Hsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: active · Automatable: no · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-79USprimaryCWE-79US

exploits (1)

Public proof-of-concept and weaponised exploit code.

skyllpro/CVE-2021-44026-PoCBug Chain XSS (CVE-2020-35730 and CVE-2023-43770) to SQLi (CVE-2021-44026)PoC · poc_in_github

affected products (19)

Products and version ranges known to be affected.

Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Open Source Arch Linuxall versionscert_bundDEcpe:/o:archlinux:archlinux:-
n/a n/a≤ n/aenisa_euvdEU
Fedora Project Fedora≤ 32fstec_bduRU
Fedora Project Fedora≤ 33fstec_bduRU
Thomas Brderli Roundcube≤ 1.2.13fstec_bduRU
Thomas Brderli Roundcube1.3.0 → 1.3.16fstec_bduRU
Thomas Brderli Roundcube1.4.0 → 1.4.10fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 9fstec_bduRU
Сообщество свободного программного обеспечения Debian GNU/Linux≤ 10fstec_bduRU
debian debian linux= 9.0nvdUScpe:2.3:o:debian:debian_linux:*:*:*:*:*:*:*:*
fedoraproject fedora= 32nvdUScpe:2.3:o:fedoraproject:fedora:*:*:*:*:*:*:*:*
fedoraproject fedora= 33nvdUScpe:2.3:o:fedoraproject:fedora:*:*:*:*:*:*:*:*
roundcube webmail< 1.2.13nvdUScpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail1.3.0 → 1.3.16nvdUScpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail1.4 → 1.4.10nvdUScpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
Bitnami roundcube< 1.2.13osvUSpkg:bitnami/roundcube
Bitnami roundcube1.3.0 → 1.3.16osvUSpkg:bitnami/roundcube
Bitnami roundcube1.4.0 → 1.4.10osvUSpkg:bitnami/roundcube

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-1546Roundcube: Schwachstelle ermöglicht Cross-Site ScriptingDeutsch2020-12-27csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann eine Schwachstelle in Roundcube ausnutzen, um einen Cross-Site Scripting Angriff durchzuführen.
BIT-roundcube-2020-357302024-03-06vendor · osvUS
An XSS issue was discovered in Roundcube Webmail before 1.2.13, 1.3.x before 1.3.16, and 1.4.x before 1.4.10. The attacker can send a plain text e-mail message, with JavaScript in a link reference element that is mishandled by linkref_addindex in rcube_string_replacer.php.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund nvd osv NVD CVE.org MITRE

published 2020-12-28modified 2026-06-17

related (52,973)

Related entries.

ID	severity	EPSS	exploitable	published
CVE-2026-42897US	medium6.1OT critical	70.7% (99th)	KEV	2026-05-14
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network…
CVE-2025-66376US	medium6.1OT critical	20.2% (97th)	KEV	2026-01-05
Zimbra Collaboration (ZCS) 10 before 10.0.18 and 10.1 before 10.1.13 allows Classic UI stored XSS via Cascading Style Sheets (CSS) @import directives in an HTML e-mail message.
CVE-2025-68461US	medium6.1OT critical	27.4% (98th)	KEV	2025-12-18
Roundcube Webmail before 1.5.12 and 1.6 before 1.6.12 is prone to a Cross-Site-Scripting (XSS) vulnerability via the animate tag in an SVG document.
CVE-2025-48700US	—OT critical	1.71% (77th)	KEV	2025-06-23
An issue was discovered in Zimbra Collaboration (ZCS) 8.8.15 and 9.0 and 10.0 and 10.1. A Cross-Site Scripting (XSS) vulnerability in the Zimbra Classic UI allows attackers to exec…
CVE-2025-27915US	—OT critical	4.06% (91st)	KEV	2025-03-12
An issue was discovered in Zimbra Collaboration (ZCS) 9.0 and 10.0 and 10.1. A stored cross-site scripting (XSS) vulnerability exists in the Classic Web Client due to insufficient…

+52968 more

references (31)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan