How severe is CVE-2021-39249?

CVE-2021-39249 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-2021-39249 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-39249?

CVE-2021-39249 affects Invisioncommunity Invision Power Board. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-39249?

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

When was CVE-2021-39249 published?

CVE-2021-39249 was published on 2021-08-17 and last updated on 2026-06-17.

CVE-2021-39249

CVE-2021-39249 is a medium-severity vulnerability in Invisioncommunity Invision Power Board 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-330.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 4.3
EPSS exploit prediction: 1% (51st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-330
Affected product: Invisioncommunity Invision Power Board
Published: 2021-08-17
Last modified: 2026-06-17

Description

Invision Community (aka IPS Community Suite or IP-Board) before 4.6.5.1 allows reflected XSS because the filenames of uploaded files become predictable through a brute-force attack against the PHP mt_rand function.

Frequently asked questions

What is CVE-2021-39249?: Invision Community (aka IPS Community Suite or IP-Board) before 4.6.5.1 allows reflected XSS because the filenames of uploaded files become predictable through a brute-force attack against the PHP mt_rand function.
How severe is CVE-2021-39249?: CVE-2021-39249 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-2021-39249 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (51st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-39249?: CVE-2021-39249 affects Invisioncommunity Invision Power Board. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-39249?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-39249 published?: CVE-2021-39249 was published on 2021-08-17 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:invisioncommunity:invision_power_board:*:*:*:*:*:*:*:*

More vulnerabilities in Invisioncommunity Invision Power Board

CVE-2012-5692 — Critical (CVSS 10.0): Unspecified vulnerability in admin/sources/base/core.php in Invision Power Board (aka IPB or IP.Board) 3.1.x through…
CVE-2013-3725 — Critical (CVSS 9.8): Invision Power Board (IPB) through 3.x allows admin account takeover leading to code execution.
CVE-2012-2226 — Critical (CVSS 9.8): Invision Power Board before 3.3.1 fails to sanitize user-supplied input which could allow remote attackers to obtain…
CVE-2017-8898 — Critical (CVSS 9.8): Invision Power Services (IPS) Community Suite 4.1.19.2 and earlier has stored XSS in the Announcements, allowing…
CVE-2014-4928 — High (CVSS 8.8): SQL injection vulnerability in Invision Power Board (aka IPB or IP.Board) before 3.4.6 allows remote attackers to…
CVE-2017-8899 — High (CVSS 8.1): Invision Power Services (IPS) Community Suite 4.1.19.2 and earlier has a composite of Stored XSS and Information…

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