CVE-2023-44386 | Incorrect request error handling triggers server crash in Vapor

Vapor is an HTTP web framework for Swift. There is a denial of service vulnerability impacting all users of affected versions of Vapor. The HTTP1 error handler closed connections when HTTP parse errors occur instead of passing them on. The issue is fixed as of Vapor release 4.84.2.

Published: 2023-10-05 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-44386 is rated Low Risk (37/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.60%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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-2023-44386

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 2026-06-15 0.05% 0.60% +0.55%
2 2025-11-21 0.27% 0.05% -0.22%
3 2025-11-18 — 0.27% —

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-44386

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L 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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L 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:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 3.9 1.4 [email protected]

Weakness enumeration for CVE-2023-44386

GitHub Security Advisory for CVE-2023-44386

GHSA-3mwq-h3g6-ffhm · Severity: medium · Ecosystem: swift — Vapor's incorrect request error handling triggers server crash

Affected software / configurations for CVE-2023-44386

Vendor Product Version Raw CPE
vapor vapor >= 4.83.2, < 4.84.2 cpe:2.3:a:vapor:vapor:*:*:*:*:*:*:*:*

References for CVE-2023-44386

cvelogic Threat Intelligence