VulnerabilityPublished 23 Oct 2026Updated 27 Oct 2026

CVE-2026-114726: Roundcube · [Fix mail header injection via the From display-name in the Bounce (resend) action]

Affects roundcubeSource GCVE Database

Authoritative record:CVE-2026-114726· Medium 5.8

Not known to be exploited · CVSS 5.8 Medium.

Data as of 27 Oct 2026, 06:59 UTC

CVSS 3.1 base score

5.8Medium

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

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
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: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
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: 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: 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 22 Oct 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

Affected software

Product	Affected	Fixed in
Ubuntu 26.10roundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=stonking`Other threats	Affected =1.6.11+dfsg-1	Fixed in–
Ubuntu Pro 26.04 LTSroundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=esm-apps/resolute`Other threats	Affected =1.6.11+dfsg-1 =1.6.11+dfsg-1ubuntu0.26.04.1~esm1	Fixed in–
Ubuntu Pro 24.04 LTSroundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=esm-apps/noble`Other threats	Affected 1.6.2+dfsg-1 – 1.6.6+dfsg-2ubuntu0.1+esm3 9 affected builds	Fixed in–
Ubuntu Pro 22.04 LTSroundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=esm-apps/jammy`Other threats	Affected 1.4.11+dfsg.1-4 – 1.5.0+dfsg.1-2ubuntu0.1~esm6 8 affected builds	Fixed in–
Ubuntu Pro 20.04 LTSroundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=esm-apps/focal`Other threats	Affected 1.3.8+dfsg.1-2 – 1.4.3+dfsg.1-1ubuntu0.1~esm8 14 affected builds	Fixed in–
Ubuntu Pro 18.04 LTSroundcube`pkg:deb/ubuntu/roundcube?arch=source&distro=esm-apps/bionic`Other threats	Affected 1.3.0+dfsg.1-1 – 1.3.6+dfsg.1-1ubuntu0.1~esm8 13 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The information provided does not include explicit patch or remediation details. Users should monitor official Roundcube advisories for updates and apply any released patches addressing this vulnerability. Until a fix is applied, avoid using the Bounce (resend) action with untrusted input in the From display-name field.

Description

A mail header injection vulnerability exists in Roundcube via the From display-name in the Bounce (resend) action. This flaw allows an attacker to inject malicious content into email headers when resending bounced emails. The vulnerability affects multiple specific versions of Roundcube. The CVSS score is 5.8, indicating a medium severity impact primarily on email integrity.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 27 Oct 2026, 06:59 UTC

Technical details

References

Community reviews

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