CVE-2025-53538 | Suricata's mishandling of data on HTTP2 stream 0 can lead to resource starvation

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.

Published: 2025-07-22 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-53538 is rated Moderate Risk (52/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.42%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-53538

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-18 0.05% 0.42% +0.36%
2 2025-12-30 0.05% 0.05% +0.01%
3 2025-12-18 — 0.05% —

Full EPSS history (5 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-53538

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2025-53538

OS Trackers for CVE-2025-53538

vendor priority summary link
alpine — CVE-2025-53538: 1 source package rows (suricata); 15 state rows across 3 repos (3.22-community, 3.23-community, edge-community); fixed 0, open 15. https://security.alpinelinux.org/vuln/CVE-2025-53538
debian not yet assigned CVE-2025-53538 not yet assigned priority: Debian including 1 source packages (suricata), 4 status rows across 4 suites (bullseye, forky, sid, trixie): resolved 3, open 1. https://security-tracker.debian.org/tracker/CVE-2025-53538
ubuntu medium CVE-2025-53538 medium priority: Ubuntu including 1 source packages (suricata), 7 status rows across 7 suites (bionic, jammy, noble, plucky, questing, upstream, xenial): needs-triage 6, ignored 1. https://ubuntu.com/security/CVE-2025-53538

Affected software / configurations for CVE-2025-53538

Vendor Product Version Raw CPE
oisf suricata < 7.0.11 cpe:2.3:a:oisf:suricata:*:*:*:*:*:*:*:*
oisf suricata 8.0.0 cpe:2.3:a:oisf:suricata:8.0.0:beta1:*:*:*:*:*:*
oisf suricata 8.0.0 cpe:2.3:a:oisf:suricata:8.0.0:rc1:*:*:*:*:*:*

References for CVE-2025-53538

cvelogic Threat Intelligence