How severe is CVE-2025-42599?

No CVSS score has been assigned to CVE-2025-42599 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2025-42599?

Affected package information for CVE-2025-42599 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2025-42599?

No fixed release is recorded for CVE-2025-42599 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.

How do I detect CVE-2025-42599 in my code and dependencies?

Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).

How do I mitigate CVE-2025-42599 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2025-42599 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-42599 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-42599?

CVE-2025-42599 has an EPSS (Exploit Prediction Scoring System) score of 3.4%, placing it in the 89th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Is CVE-2025-42599 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2025-42599 (Qualitia Active! Mail Stack-Based Buffer Overflow Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2025-04-28. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-05-19. The required action was: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2025-42599?

CVE-2025-42599 is classified as CWE-121 (CWE-121). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2025-42599 published, and has it been updated?

CVE-2025-42599 was published on April 18, 2025 and was last updated on February 26, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CISA KEV · ACTIVELY EXPLOITED

CVE-2025-42599

CVE-2025-42599 is a CWE-121 vulnerability. It is in CISA's Known Exploited Vulnerabilities catalog (added 2025-04-28) — treat it as actively exploited and patch now. No vendor fix is recorded yet; mitigation options are listed below.

Active! mail 6 BuildInfo: 6.60.05008561 and earlier contains a stack-based buffer overflow vulnerability. Receiving a specially crafted request created and sent by a remote unauthenticated…

Published

Apr 18, 2025

Updated

Feb 26, 2026

Affected

1 product

Patched

See advisory

Exploits

None indexed

Exploitation data as of Oct 22, 2026 · OSV.dev, NVD, CISA KEV, FIRST.org (EPSS)

Exploitation Status

Actively exploited in the wild

Confirmed by CISA's Known Exploited Vulnerabilities catalog on 2025-04-28. Federal agencies were required to remediate by 2025-05-19.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
A successful exploit gives an attacker total control of the affected component, not partial access.

Exploitation and automatability from CISA (KEV catalog and SSVC triage) for CVE-2025-42599.

EPSS Exploitation Probability

via FIRST.org ↗

3.4%probability of exploitation in next 30 days

Lower Risk+0.06%

Lower risk than most CVEs89th percentile — riskier than 89% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Description

Active! mail 6 BuildInfo: 6.60.05008561 and earlier contains a stack-based buffer overflow vulnerability. Receiving a specially crafted request created and sent by a remote unauthenticated attacker may lead to arbitrary code execution and/or a denial-of-service (DoS) condition.

Affected Products

1 product · 1 configurations

Application

active\! mailqualitia

< 6.60.05008562

range

Detection & mitigation playbook

Vulnerability

Detect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Remediation status
No fixed release is recorded for CVE-2025-42599 yet. Track the upstream advisory, and apply the exposure-reduction steps below in the meantime.
Mitigate without a patch
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Frequently Asked Questions

O3 Security · Impact-Aware SCA

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