How severe is CVE-2025-53538?

CVE-2025-53538 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-2025-53538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-53538?

CVE-2025-53538 primarily affects Oisf Suricata. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2025-53538?

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-2025-53538 have an EU (EUVD) identifier?

Yes. CVE-2025-53538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-22378.

When was CVE-2025-53538 published?

CVE-2025-53538 was published on 2025-07-22 and last updated on 2026-06-17.

CVE-2025-53538

CVE-2025-53538 is a high-severity vulnerability in Oisf Suricata 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-400.

Key facts

Severity: High (CVSS 3.x base score 7.5)
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-22378
Weakness: CWE-400
Affected product: Oisf Suricata
Published: 2025-07-22
Last modified: 2026-06-17

Description

Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. In versions 7.0.10 and below and 8.0.0-beta1 through 8.0.0-rc1, mishandling of data on HTTP2 stream 0 can lead to uncontrolled memory usage, leading to loss of visibility. Workarounds include disabling the HTTP/2 parser, and using a signature like drop http2 any any -> any any (frame:http2.hdr; byte_test:1,=,0,3; byte_test:4,=,0,5; sid: 1;) where the first byte test tests the HTTP2 frame type DATA and the second tests the stream id 0. This is fixed in versions 7.0.11 and 8.0.0.

Frequently asked questions

What is CVE-2025-53538?: Suricata is a network IDS, IPS and NSM engine developed by the OISF (Open Information Security Foundation) and the Suricata community. In versions 7.0.10 and below and 8.0.0-beta1 through 8.0.0-rc1, mishandling of data on HTTP2 stream 0 can lead to uncontrolled memory usage, leading to loss of visibility. Workarounds include disabling the HTTP/2 parser, and using a signature like drop http2 any any -> any any (frame:http2.hdr; byte_test:1,=,0,3; byte_test:4,=,0,5; sid: 1;) where the first byte test tests the HTTP2 frame type DATA and the second tests the stream id 0. This is fixed in versions 7.0.11 and 8.0.0.
How severe is CVE-2025-53538?: CVE-2025-53538 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-2025-53538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-53538?: CVE-2025-53538 primarily affects Oisf Suricata. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-53538?: 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-2025-53538 have an EU (EUVD) identifier?: Yes. CVE-2025-53538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-22378.
When was CVE-2025-53538 published?: CVE-2025-53538 was published on 2025-07-22 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:oisf:suricata:*:*:*:*:*:*:*:*
cpe:2.3:a:oisf:suricata:8.0.0:beta1:*:*:*:*:*:*
cpe:2.3:a:oisf:suricata:8.0.0:rc1:*:*:*:*:*:*

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