How severe is CVE-2023-45556?

CVE-2023-45556 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2023-45556 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-45556?

CVE-2023-45556 affects Mybb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-45556?

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

When was CVE-2023-45556 published?

CVE-2023-45556 was published on 2023-11-06 and last updated on 2026-06-17.

CVE-2023-45556

CVE-2023-45556 is a medium-severity vulnerability in Mybb with a CVSS 3.x base score of 5.4. 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 5.4)
EPSS exploit prediction: 1% (41st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Mybb
Published: 2023-11-06
Last modified: 2026-06-17

Description

Cross Site Scripting vulnerability in Mybb Mybb Forums v.1.8.33 allows a local attacker to execute arbitrary code via the theme Name parameter in the theme management component.

Frequently asked questions

What is CVE-2023-45556?: Cross Site Scripting vulnerability in Mybb Mybb Forums v.1.8.33 allows a local attacker to execute arbitrary code via the theme Name parameter in the theme management component.
How severe is CVE-2023-45556?: CVE-2023-45556 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2023-45556 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (41st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-45556?: CVE-2023-45556 affects Mybb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-45556?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-45556 published?: CVE-2023-45556 was published on 2023-11-06 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mybb:mybb:*:*:*:*:*:*:*:*

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CVE-2006-0218 — Critical (CVSS 10.0): Multiple unspecified vulnerabilities in MyBulletinBoard (MyBB) before 1.0.2 have unspecified impact and attack vectors,…
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CVE-2020-22612 — Critical (CVSS 9.8): Installer RCE on settings file write in MyBB before 1.8.22.

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