CVE-2026-26079: Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13 allows Cascading Style Sheets (CSS) injection, e.g., because comments are mishandled.
Noroxi assessment
Priority: Monitor (action score 18/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.35% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: Roundcube Webmail 1.5.13, 1.6.13.
Low priority for now. Upgrade to Roundcube Webmail 1.5.13, 1.6.13 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
- Published
- Feb 11, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.3% · 29th percentile
- CWE
- CWE-829
Report tools
Action score
18
Low priority for now.
- CVSS
- 18 / 40 · 4.7 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.3%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- —
- CNA · mitre
- 4.7
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
Is your version affected? Check itNoroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
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Versions reported by the vendor
Affected version ranges reported by the assigning authority (mitre). Independent of NVD's CPE analysis and usually ahead of it.
Roundcube Webmail
- before 1.5.13affected · semver
- 1.6.0 and later · before 1.6.13affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:11 | roundcube | before 1.4.15+dfsg.1-1+deb11u7 | 1.4.15+dfsg.1-1+deb11u7 |
| Debian:12 | roundcube | before 1.6.5+dfsg-1+deb12u7 | 1.6.5+dfsg-1+deb12u7 |
| Debian:13 | roundcube | before 1.6.13+dfsg-0+deb13u1 | 1.6.13+dfsg-0+deb13u1 |
| Debian:14 | roundcube | before 1.6.13+dfsg-1 | 1.6.13+dfsg-1 |
| openSUSE:Leap 16.0 | roundcubemail | before 1.6.13-bp160.1.1 | 1.6.13-bp160.1.1 |
Same product
roundcube: all recordsOther highest-scoring records for the same primary product.
- CVE-2025-49113Roundcube Webmail before 1.5.10 and 1.6.x before 1.6.11 allows remote code execution by authenticated users because the _from parameter in…KEV95Now
- CVE-2020-12641rcube_image.php in Roundcube Webmail before 1.4.4 allows attackers to execute arbitrary code via shell metacharacters in a configuration…KEV94Now
- CVE-2024-42009A Cross-Site Scripting vulnerability in Roundcube through 1.5.7 and 1.6.x through 1.6.7 allows a remote attacker to steal and send emails…KEV92Now
Published before and after this one in the same product
- ← EarlierCVE-2025-68461Dec 18, 2025 · 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…KEV62This week
- ← EarlierCVE-2026-25916Feb 9, 2026 · Roundcube Webmail before 1.5.13 and 1.6 before 1.6.13, when "Block remote images" is used, does not block SVG feImage.17Monitor
- Later →CVE-2026-35537Apr 3, 2026 · An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14.30Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Roundcube Webmail | 1.5.13 | Vendor (CNA) |
| Roundcube Webmail | 1.6.13 | Vendor (CNA) |
| debian:roundcube | 1.6.5+dfsg-1+deb12u7 · Debian:12 | Package registry (OSV) |
| opensuse:roundcubemail | 1.6.13-bp160.1.1 · openSUSE:Leap 16.0 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
- CVE-2026-114727253 days apartRoundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 passes potentially unsafe content into ImageMagick when resizing images.33Monitor
Bug bounty scope
The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.
Not on record for this CVE: EPSS history · researcher credit.
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- low · data can be read
- Integrity
- none
- Availability
- none
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality impact
- Low
- Integrity impact
- None
- Availability impact
- None
Weakness class (CWE)
CWE-829 · Inclusion of Functionality from Untrusted Control SphereCVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Code InclusionCAPEC-175likelihood: Medium · Very High
- Serialized Data External LinkingCAPEC-201likelihood: High · High
- DTD InjectionCAPEC-228Medium
- Local Code InclusionCAPEC-251Medium
- PHP Local File InclusionCAPEC-252Medium
- Remote Code InclusionCAPEC-253
- Force Use of Corrupted FilesCAPEC-263Medium
- Open-Source Library ManipulationCAPEC-538likelihood: Low · High
ATT&CK techniques
- Process InjectionT1055
- Browser ExtensionsT1176
- Supply Chain Compromise: Software Dependencies and Development ToolsT1195.001
- Server Software Component: IIS ComponentsT1505.004
- Server Software Component: Terminal Services DLLT1505.005
- Hijack Execution Flow: Dynamic Linker HijackingT1574.006
- Hijack Execution Flow: KernelCallbackTableT1574.013
- Reflective Code LoadingT1620
Change log (1)
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (8 more)Show less
- github.com/roundcube/roundcubemail/commit/2b5625f1d2ef7e050fd1ae481b2a52dc35466447
- github.com/roundcube/roundcubemail/commit/53d75d5dfebef235a344d476b900c20c12d52b01
- github.com/roundcube/roundcubemail/commit/5a3315cce587e0be58335d11ff9a5571c90494a5
- github.com/roundcube/roundcubemail/commit/bf89cbaa5897d8ad62e8057d9a3f6babb90b7954
- github.com/roundcube/roundcubemail/commit/c15f5dbf093a497e19a749b20e7f8fb5a9c24cde
- github.com/roundcube/roundcubemail/releases/tag/1.5.13
- github.com/roundcube/roundcubemail/releases/tag/1.6.13
- roundcube.net/news/2026/02/08/security-updates-1.6.13-and-1.5.13
Vendor advisories and official records. Exploit/PoC links are deliberately left out.