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Full vulnerability report · 2026
CVE-2026-55484High confidence

ALOS HTTP: Unauthenticated remote DoS: malformed path starting with "?" triggers out-of-bounds panic in sanitizeRequestPath, crashing entire server

guno1928 · alos-http

7.5HighCVSS 3.1
Recommended action
Within 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2026-67872

No EUVD known-exploited evidence

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.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
7.5 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity with public exploit material referenced by a structured source; prioritise exposed affected systems while verifying vendor guidance.

Fix not verified
01

What, why and how

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.

What

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.

Why

An exception is thrown from a function, but it is not caught.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

An exception is thrown from a function, but it is not caught.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
Reference recorded

CISA Vulnrichment records proof-of-concept exploitation in its SSVC data. BlackTree has not independently executed or validated exploit material.

Likely attack path
a network path → Uncaught Exception → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-248 ↗

CWE-248: Uncaught Exception. An exception is thrown from a function, but it is not caught.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-248Public exploit reference
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-67872Official EUVD mapping

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.

Official EUVD record
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Fix not verified
Affected
< 0.0.0-20260617230736-314b6783e196
Fixed
No fixed version is explicitly recorded in the structured CVE data.
Action
No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 28 Aug 2026 · Last source change 28 Aug 2026, 20:00 UTC · CWE-248 · Uncaught Exception

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-29
European sourceENISA EUVD · EUVD-2026-67872
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceCNA
NVD statusNVD not scheduled

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →
  1. ENISA EUVD mappingEUVD-2026-67872 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2026-67872"}
    ENISA EUVD ↗
  2. Public exploit evidencePublic exploit evidence changed from No public exploit to Public exploit reference.
    Before
    No public exploit
    After
    Public exploit reference
    CVE.org ↗
  3. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
ENISA EUVD · EUVD-2026-67872↗CISA Vulnrichment SSVC evidence↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2026-55484 · cve.blacktree.nl