How severe is CVE-2026-33511?

CVE-2026-33511 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-33511 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33511?

CVE-2026-33511 primarily affects Pyload. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-33511?

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

Does CVE-2026-33511 have an EU (EUVD) identifier?

Yes. CVE-2026-33511 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-15001.

When was CVE-2026-33511 published?

CVE-2026-33511 was published on 2026-03-24 and last updated on 2026-06-17.

CVE-2026-33511

CVE-2026-33511 is a critical-severity vulnerability in Pyload with a CVSS 3.x base score of 9.8. 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-639.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 8.8
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-15001
Weakness: CWE-639
Affected product: Pyload
Published: 2026-03-24
Last modified: 2026-06-17

Description

pyLoad is a free and open-source download manager written in Python. From version 0.4.20 to before version 0.5.0b3.dev97, the local_check decorator in pyLoad's ClickNLoad feature can be bypassed by any remote attacker through HTTP Host header spoofing. This allows unauthenticated remote users to access localhost-restricted endpoints, enabling them to inject arbitrary downloads, write files to the storage directory, and execute JavaScript code. This issue has been patched in version 0.5.0b3.dev97.

Frequently asked questions

What is CVE-2026-33511?: pyLoad is a free and open-source download manager written in Python. From version 0.4.20 to before version 0.5.0b3.dev97, the local_check decorator in pyLoad's ClickNLoad feature can be bypassed by any remote attacker through HTTP Host header spoofing. This allows unauthenticated remote users to access localhost-restricted endpoints, enabling them to inject arbitrary downloads, write files to the storage directory, and execute JavaScript code. This issue has been patched in version 0.5.0b3.dev97.
How severe is CVE-2026-33511?: CVE-2026-33511 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-33511 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (34th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33511?: CVE-2026-33511 primarily affects Pyload. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-33511?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-33511 have an EU (EUVD) identifier?: Yes. CVE-2026-33511 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-15001.
When was CVE-2026-33511 published?: CVE-2026-33511 was published on 2026-03-24 and last updated on 2026-06-17.

References

https://github.com/pyload/pyload/security/advisories/GHSA-g5j2-gxqh-x7pw

Affected products (2)

cpe:2.3:a:pyload:pyload:*:*:*:*:*:*:*:*
cpe:2.3:a:pyload-ng_project:pyload-ng:*:*:*:*:*:python:*:*

More vulnerabilities in Pyload

CVE-2023-0435 — Critical (CVSS 9.8): Excessive Attack Surface in GitHub repository pyload/pyload prior to 0.5.0b3.dev41.
CVE-2023-0297 — Critical (CVSS 9.8): Code Injection in GitHub repository pyload/pyload prior to 0.5.0b3.dev31.
CVE-2024-47821 — Critical (CVSS 9.1): pyLoad is a free and open-source Download Manager. The folder `/.pyload/scripts` has scripts which are run when certain…
CVE-2024-32880 — Critical (CVSS 9.1): pyload is an open-source Download Manager written in pure Python. An authenticated user can change the download folder…
CVE-2026-41133 — High (CVSS 8.8): pyLoad is a free and open-source download manager written in Python. Versions up to and including 0.5.0b3.dev97 cache…
CVE-2023-47890 — High (CVSS 8.8): pyLoad 0.5.0 is vulnerable to Unrestricted File Upload.

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