How severe is CVE-2023-53979?

CVE-2023-53979 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2023-53979 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2023-53979?

CVE-2023-53979 affects Mybb. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2023-53979?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2023-53979 have an EU (EUVD) identifier?

Yes. CVE-2023-53979 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-60241.

When was CVE-2023-53979 published?

CVE-2023-53979 was published on 2025-12-22 and last updated on 2026-06-17.

CVE-2023-53979

CVE-2023-53979 is a high-severity vulnerability in Mybb with a CVSS 3.x base score of 8.8. 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-22.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v4: 8.6
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2023-60241
Weakness: CWE-22
Affected product: Mybb
Published: 2025-12-22
Last modified: 2026-06-17

Description

MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface.

Frequently asked questions

What is CVE-2023-53979?: MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface.
How severe is CVE-2023-53979?: CVE-2023-53979 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2023-53979 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-53979?: CVE-2023-53979 affects Mybb. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-53979?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2023-53979 have an EU (EUVD) identifier?: Yes. CVE-2023-53979 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2023-60241.
When was CVE-2023-53979 published?: CVE-2023-53979 was published on 2025-12-22 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:mybb:mybb:1.8.32:*:*:*:*:*:*:*

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