VulnerabilityPublished 17 Aug 2026

CVE-2026-75010: Roundcube Webmail · Incorrect Resource Transfer Between Spheres

Affects Roundcube WebmailSource CVE Database V5

Not known to be exploited · CVSS 6.4 Medium : upgrade to 1.7.3 or 1.6.18 when convenient.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

6.4Medium

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

EPSS

0.3% chance of exploitation in 30 days – higher than 33% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-08-17.

Patch

Available – fixed in 1.7.3, 1.6.18

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: Low
User Interaction: None
Scope: Changed
Confidentiality: Low
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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to 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 17 Aug 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.

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.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, 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 Roundcube Webmail to 1.7.3 or 1.6.18.

Affected software

Product	Affected	Fixed in
RoundcubeWebmail	Affected >=1.7.0 <1.7.3	Fixed in 1.7.3
RoundcubeWebmail	Affected >=1.6.0 <1.6.18	Fixed in 1.6.18

AI-suggested

Upgrade Roundcube Webmail to version 1.6.18 or later, or 1.7.3 or later, where this vulnerability is fixed. No other mitigations are indicated by the vendor advisory.

Description

CVE-2026-75010 is a vulnerability in Roundcube Webmail versions before 1.6.18 and 1.7.x before 1.7.3. It affects instances using the password plugin with the modoboa driver, where a crafted session can leak a Modoboa API authentication token to a user-controlled host. This could lead to limited confidentiality and integrity impacts but does not affect availability.

Impact

An attacker with low privileges can exploit this vulnerability remotely to leak an authentication token, potentially compromising confidentiality and integrity of the Modoboa API integration within affected Roundcube Webmail instances. There is no impact on availability. No known exploits are reported in the wild.

Summary

In Roundcube Webmail versions >=1.6.0 <1.6.18 and >=1.7.0 <1.7.3, the modoboa driver of the password plugin improperly handles session data, allowing an attacker to leak a Modoboa API authentication token to a user-controlled host. This is classified as CWE-669 (Incorrect Resource Transfer Between Spheres). The vulnerability has a CVSS v3.1 base score of 6.4, indicating a medium severity with network attack vector, low attack complexity, and requiring low privileges but no user interaction. The issue was fixed in versions 1.6.18 and 1.7.3.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 09:26 UTC

WeaknessesCWE-669

Technical details

References

Community reviews

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