CVE-2026-44217: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in rexxars sse-channel
CVE-2026-44217 is a medium severity vulnerability in the rexxars sse-channel library prior to version 4. 0. 1. It involves improper neutralization of CRLF sequences (CRLF Injection) in the event, retry, or id fields of server-sent events. This flaw allows an attacker to inject arbitrary messages into the SSE stream, leading to potential event spoofing. The vulnerability is fixed in version 4. 0. 1. No known exploits are reported in the wild.
AI Analysis
Technical Summary
The rexxars sse-channel library, used for server-sent events in Node.js HTTP request/response streams, prior to version 4.0.1, improperly neutralizes CRLF sequences in user-supplied values for event, retry, or id fields. This vulnerability (CWE-93) enables an attacker to perform event spoofing by injecting arbitrary messages into the SSE stream. The issue is resolved in version 4.0.1. The CVSS 4.0 base score is 6.6, reflecting a medium severity with network attack vector and no privileges or user interaction required.
Potential Impact
An attacker can inject arbitrary messages into the SSE stream, potentially misleading clients consuming the stream by spoofing events. This could affect the integrity of the event data received by clients. There is no indication of privilege escalation, confidentiality, or availability impact. No known exploits have been reported in the wild.
Mitigation Recommendations
Upgrade to rexxars sse-channel version 4.0.1 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 4.0.1, applying this official update fully mitigates the issue. No additional mitigations are specified or required.
CVE-2026-44217: CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection') in rexxars sse-channel
Description
CVE-2026-44217 is a medium severity vulnerability in the rexxars sse-channel library prior to version 4. 0. 1. It involves improper neutralization of CRLF sequences (CRLF Injection) in the event, retry, or id fields of server-sent events. This flaw allows an attacker to inject arbitrary messages into the SSE stream, leading to potential event spoofing. The vulnerability is fixed in version 4. 0. 1. No known exploits are reported in the wild.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The rexxars sse-channel library, used for server-sent events in Node.js HTTP request/response streams, prior to version 4.0.1, improperly neutralizes CRLF sequences in user-supplied values for event, retry, or id fields. This vulnerability (CWE-93) enables an attacker to perform event spoofing by injecting arbitrary messages into the SSE stream. The issue is resolved in version 4.0.1. The CVSS 4.0 base score is 6.6, reflecting a medium severity with network attack vector and no privileges or user interaction required.
Potential Impact
An attacker can inject arbitrary messages into the SSE stream, potentially misleading clients consuming the stream by spoofing events. This could affect the integrity of the event data received by clients. There is no indication of privilege escalation, confidentiality, or availability impact. No known exploits have been reported in the wild.
Mitigation Recommendations
Upgrade to rexxars sse-channel version 4.0.1 or later, where this vulnerability is fixed. Since the vendor advisory confirms the fix in 4.0.1, applying this official update fully mitigates the issue. No additional mitigations are specified or required.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-05T15:13:47.572Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a038bd7cbff5d8610164953
Added to database: 5/12/2026, 8:21:43 PM
Last enriched: 5/12/2026, 8:39:35 PM
Last updated: 5/12/2026, 9:49:40 PM
Views: 3
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