CVE-2026-55484

CVE-2026-55484 is a high-severity vulnerability 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-248.

Key facts

Description

ALOS HTTP is a Linux-first Go web framework and application server built around a custom networking stack. Prior to 0.0.0-20260617230736-314b6783e196, core/utils.go::sanitizeRequestPath calls splitPathQuery on a request path beginning with a question mark and then performs the unchecked p[0] access without checking whether the resulting path is empty. An unauthenticated client can send a malformed request such as a question-mark-only path through h1_plain.go::ParseH1RequestHead, hpack.go::decodeSimpleGetPathHTTPSRequest, hpack.go::observeHeader, or h3_conn.go::handleRequestStream, causing an out-of-bounds panic before core.Recovery() middleware runs and terminating the server process. This issue is fixed in pseudo-version 0.0.0-20260617230736-314b6783e196.

Frequently asked questions

What is CVE-2026-55484?
ALOS HTTP is a Linux-first Go web framework and application server built around a custom networking stack. Prior to 0.0.0-20260617230736-314b6783e196, core/utils.go::sanitizeRequestPath calls splitPathQuery on a request path beginning with a question mark and then performs the unchecked p[0] access without checking whether the resulting path is empty. An unauthenticated client can send a malformed request such as a question-mark-only path through h1_plain.go::ParseH1RequestHead, hpack.go::decodeSimpleGetPathHTTPSRequest, hpack.go::observeHeader, or h3_conn.go::handleRequestStream, causing an out-of-bounds panic before core.Recovery() middleware runs and terminating the server process. This issue is fixed in pseudo-version 0.0.0-20260617230736-314b6783e196.
How severe is CVE-2026-55484?
CVE-2026-55484 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-2026-55484 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-55484?
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.
When was CVE-2026-55484 published?
CVE-2026-55484 was published on 2026-08-28 and last updated on 2026-09-09.

References

Other CWE-248 vulnerabilities

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