CVE-2026-35537VulnerabilityPublished 17 Apr 2026Updated 17 Sep 2026

SUSE roundcubemail · Security update for roundcubemail

Affects SUSE roundcubemailSource GCVE Database

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Authoritative record:CVE-2026-35537· Low 3.7

Not known to be exploited · CVSS 3.7 Low : upgrade the Debian roundcubemail package to 1.6.15 when convenient.

Data as of 31 Oct 2026, 20:20 UTC

CVSS 3.1 base score

3.7Low

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.6.15

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: High
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: High: A successful attack depends on conditions beyond the attacker's control. That is, a successful attack cannot be accomplished at will, but requires the attacker to invest in some measurable amount of effort in preparation or execution against the vulnerable component before a successful attack can be expected. For example, a successful attack may require an attacker to: gather knowledge about the environment in which the vulnerable target/component exists; prepare the target environment to improve exploit reliability; or inject themselves into the logical network path between the target and the resource requested by the victim in order to read and/or modify network communications (e.g., a man in the middle attack).
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 3 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 31 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade the Debian roundcubemail package to 1.6.15.

Affected software

Product	Affected	Fixed in
Debianroundcubemail`pkg:deb/roundcubemail`Other threats	Affected <1.6.15	Fixed in 1.6.15

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AI-suggested

A security update is available in Roundcube Webmail stable version 1.6.15 which addresses these vulnerabilities. It is strongly recommended to update all productive installations of Roundcube 1.6.x to version 1.6.15. Users should backup their data before updating. No additional vendor advisories indicate alternative mitigations or that no action is required.

Description

This security update for Roundcube Webmail 1.6 addresses multiple vulnerabilities including a pre-authentication arbitrary file write via unsafe deserialization in the redis/memcache session handler (CVE-2026-35537). Additional fixes include prevention of unauthorized password changes, IMAP injection and CSRF bypass in mail search, remote image blocking bypasses via SVG animate attributes and crafted body background attributes, XSS in HTML attachment preview, and SSRF with information disclosure via stylesheet links. The update also resolves regressions affecting mail search with non-ASCII criteria and data URL image handling. Users of Roundcube 1.6.x are recommended to update to version 1.6.15 to mitigate these issues.

Impact

The vulnerabilities fixed include a high-severity pre-auth arbitrary file write that could allow attackers to write files without authentication, potentially leading to code execution or system compromise. Other issues fixed could allow unauthorized password changes, cross-site request forgery, injection attacks, cross-site scripting, server-side request forgery, and information disclosure. The remote image loading bypasses could undermine privacy protections by allowing tracking or unwanted content loading. These combined issues pose significant risks to confidentiality, integrity, and availability of Roundcube Webmail installations.

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What to do

Affected software

Description

AI analysisMachine-generated, updated 17 Sep 2026, 02:27 UTC

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