How severe is CVE-2025-53537?

CVE-2025-53537 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2025-53537 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-2025-53537?

CVE-2025-53537 affects Oisf Libhtp. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-53537?

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

Does CVE-2025-53537 have an EU (EUVD) identifier?

Yes. CVE-2025-53537 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-22472.

When was CVE-2025-53537 published?

CVE-2025-53537 was published on 2025-07-23 and last updated on 2026-06-17.

CVE-2025-53537

CVE-2025-53537 is a high-severity vulnerability in Oisf Libhtp with a CVSS 3.x base score of 7.5. 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-401.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (34th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-22472
Weakness: CWE-401
Affected product: Oisf Libhtp
Published: 2025-07-23
Last modified: 2026-06-17

Description

LibHTP is a security-aware parser for the HTTP protocol and its related bits and pieces. In versions 0.5.50 and below, there is a traffic-induced memory leak that can starve the process of memory, leading to loss of visibility. To workaround this issue, set `suricata.yaml app-layer.protocols.http.libhtp.default-config.lzma-enabled` to false. This issue is fixed in version 0.5.51.

Frequently asked questions

What is CVE-2025-53537?: LibHTP is a security-aware parser for the HTTP protocol and its related bits and pieces. In versions 0.5.50 and below, there is a traffic-induced memory leak that can starve the process of memory, leading to loss of visibility. To workaround this issue, set `suricata.yaml app-layer.protocols.http.libhtp.default-config.lzma-enabled` to false. This issue is fixed in version 0.5.51.
How severe is CVE-2025-53537?: CVE-2025-53537 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-53537 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-2025-53537?: CVE-2025-53537 affects Oisf Libhtp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-53537?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-53537 have an EU (EUVD) identifier?: Yes. CVE-2025-53537 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-22472.
When was CVE-2025-53537 published?: CVE-2025-53537 was published on 2025-07-23 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:oisf:libhtp:*:*:*:*:*:*:*:*

More vulnerabilities in Oisf Libhtp

CVE-2018-10243 — Critical (CVSS 9.8): htp_parse_authorization_digest in htp_parsers.c in LibHTP 0.5.26 allows remote attackers to cause a heap-based buffer…
CVE-2024-45797 — High (CVSS 7.5): LibHTP is a security-aware parser for the HTTP protocol and the related bits and pieces. Prior to version 0.5.49,…
CVE-2024-28871 — High (CVSS 7.5): LibHTP is a security-aware parser for the HTTP protocol and the related bits and pieces. Version 0.5.46 may parse…
CVE-2024-23837 — High (CVSS 7.5): LibHTP is a security-aware parser for the HTTP protocol. Crafted traffic can cause excessive processing time of HTTP…
CVE-2015-0928 — High (CVSS 7.5): libhtp 0.5.15 allows remote attackers to cause a denial of service (NULL pointer dereference).
CVE-2019-17420 — Medium (CVSS 5.3): In OISF LibHTP before 0.5.31, as used in Suricata 4.1.4 and other products, an HTTP protocol parsing error causes the…

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