How severe is CVE-2025-53633?

CVE-2025-53633 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-2025-53633 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-53633?

CVE-2025-53633 affects Ctfer-io Chall-manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-53633?

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-2025-53633 have an EU (EUVD) identifier?

Yes. CVE-2025-53633 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-21056.

When was CVE-2025-53633 published?

CVE-2025-53633 was published on 2025-07-10 and last updated on 2026-06-17.

CVE-2025-53633

CVE-2025-53633 is a critical-severity vulnerability in Ctfer-io Chall-manager 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-405.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v4: 8.7
EPSS exploit prediction: 0% (37th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-21056
Weakness: CWE-405
Affected product: Ctfer-io Chall-manager
Published: 2025-07-10
Last modified: 2026-06-17

Description

Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. When decoding a scenario (i.e. a zip archive), the size of the decoded content is not checked, potentially leading to zip bombs decompression. Exploitation does not require authentication nor authorization, so anyone can exploit it. It should nonetheless not be exploitable as it is highly recommended to bury Chall-Manager deep within the infrastructure due to its large capabilities, so no users could reach the system. Patch has been implemented by commit 14042aa and shipped in v0.1.4.

Frequently asked questions

What is CVE-2025-53633?: Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. When decoding a scenario (i.e. a zip archive), the size of the decoded content is not checked, potentially leading to zip bombs decompression. Exploitation does not require authentication nor authorization, so anyone can exploit it. It should nonetheless not be exploitable as it is highly recommended to bury Chall-Manager deep within the infrastructure due to its large capabilities, so no users could reach the system. Patch has been implemented by commit 14042aa and shipped in v0.1.4.
How severe is CVE-2025-53633?: CVE-2025-53633 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-2025-53633 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (37th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-53633?: CVE-2025-53633 affects Ctfer-io Chall-manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-53633?: 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-2025-53633 have an EU (EUVD) identifier?: Yes. CVE-2025-53633 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-21056.
When was CVE-2025-53633 published?: CVE-2025-53633 was published on 2025-07-10 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:ctfer-io:chall-manager:*:*:*:*:*:*:*:*

More vulnerabilities in Ctfer-io Chall-manager

CVE-2026-32768 — Critical (CVSS 9.9): Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. In versions prior to 0.6.5,…
CVE-2025-53632 — Critical (CVSS 9.1): Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. When decoding a scenario…
CVE-2025-53634 — High (CVSS 7.5): Chall-Manager is a platform-agnostic system able to start Challenges on Demand of a player. The HTTP Gateway processes…

All CVEs affecting Ctfer-io Chall-manager →

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