How severe is CVE-2026-35055?

CVE-2026-35055 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-35055 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-35055?

CVE-2026-35055 affects Xenforo. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-35055?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-35055 have an EU (EUVD) identifier?

Yes. CVE-2026-35055 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17741.

When was CVE-2026-35055 published?

CVE-2026-35055 was published on 2026-04-01 and last updated on 2026-06-17.

CVE-2026-35055

CVE-2026-35055 is a medium-severity vulnerability in Xenforo with a CVSS 3.x base score of 6.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v4: 5.1
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-17741
Weakness: CWE-79
Affected product: Xenforo
Published: 2026-04-01
Last modified: 2026-06-17

Description

XenForo before 2.3.9 and before 2.2.18 is vulnerable to cross-site scripting (XSS) related to lightbox usage in posts. An attacker can inject malicious scripts that execute when users interact with post content displayed in the lightbox.

Frequently asked questions

What is CVE-2026-35055?: XenForo before 2.3.9 and before 2.2.18 is vulnerable to cross-site scripting (XSS) related to lightbox usage in posts. An attacker can inject malicious scripts that execute when users interact with post content displayed in the lightbox.
How severe is CVE-2026-35055?: CVE-2026-35055 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-35055 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-35055?: CVE-2026-35055 affects Xenforo. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-35055?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-35055 have an EU (EUVD) identifier?: Yes. CVE-2026-35055 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-17741.
When was CVE-2026-35055 published?: CVE-2026-35055 was published on 2026-04-01 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:xenforo:xenforo:*:*:*:*:*:*:*:*

More vulnerabilities in Xenforo

CVE-2025-71279 — Critical (CVSS 9.8): XenForo before 2.3.7 contains a security issue affecting Passkeys that have been added to user accounts. An attacker…
CVE-2025-71281 — High (CVSS 8.8): XenForo before 2.3.7 does not properly restrict methods callable from within templates. A loose prefix match was used…
CVE-2025-71278 — High (CVSS 8.8): XenForo before 2.3.5 allows OAuth2 client applications to request unauthorized scopes. This affects any customer using…
CVE-2024-38458 — High (CVSS 8.8): Xenforo before 2.2.16 allows code injection.
CVE-2024-38457 — High (CVSS 8.8): Xenforo before 2.2.16 allows CSRF.
CVE-2024-25006 — High (CVSS 8.1): XenForo before 2.2.14 allows Directory Traversal (with write access) by an authenticated user who has permissions to…

All CVEs affecting Xenforo →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →