How severe is CVE-2021-43808?

CVE-2021-43808 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-43808 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-43808?

CVE-2021-43808 affects Laravel Framework. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-43808?

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

When was CVE-2021-43808 published?

CVE-2021-43808 was published on 2021-12-08 and last updated on 2026-06-17.

CVE-2021-43808

CVE-2021-43808 is a medium-severity vulnerability in Laravel Framework with a CVSS 3.x base score of 5.3. 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-327.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 4.3
EPSS exploit prediction: 1% (52nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-327
Affected product: Laravel Framework
Published: 2021-12-08
Last modified: 2026-06-17

Description

Laravel is a web application framework. Laravel prior to versions 8.75.0, 7.30.6, and 6.20.42 contain a possible cross-site scripting (XSS) vulnerability in the Blade templating engine. A broken HTML element may be clicked and the user taken to another location in their browser due to XSS. This is due to the user being able to guess the parent placeholder SHA-1 hash by trying common names of sections. If the parent template contains an exploitable HTML structure an XSS vulnerability can be exposed. This vulnerability has been patched in versions 8.75.0, 7.30.6, and 6.20.42 by determining the parent placeholder at runtime and using a random hash that is unique to each request.

Frequently asked questions

What is CVE-2021-43808?: Laravel is a web application framework. Laravel prior to versions 8.75.0, 7.30.6, and 6.20.42 contain a possible cross-site scripting (XSS) vulnerability in the Blade templating engine. A broken HTML element may be clicked and the user taken to another location in their browser due to XSS. This is due to the user being able to guess the parent placeholder SHA-1 hash by trying common names of sections. If the parent template contains an exploitable HTML structure an XSS vulnerability can be exposed. This vulnerability has been patched in versions 8.75.0, 7.30.6, and 6.20.42 by determining the parent placeholder at runtime and using a random hash that is unique to each request.
How severe is CVE-2021-43808?: CVE-2021-43808 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-43808 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (52nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-43808?: CVE-2021-43808 affects Laravel Framework. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-43808?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-43808 published?: CVE-2021-43808 was published on 2021-12-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:laravel:framework:*:*:*:*:*:*:*:*

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