CVE-2026-44217: rexxars sse-channel · CRLF Injection
Affects rexxars sse-channelSource CVE Database V5
Not known to be exploited · CVSS 6.6 Medium : upgrade to 4.0.1 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 41% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 4.0.1
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:UExploitation evidence
Disclosed: evidence found.
CVE published 12 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade sse-channel and rexxars/sse-channel to 4.0.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| rexxarssse-channel | Affected
| Fixed in
|
npmrexxars/sse-channelpkg:npm/rexxars/sse-channelOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade to sse-channel version 4.0.1 or later, where this vulnerability is fixed. Since the vendor advisory does not provide additional remediation details, applying this official fix is the recommended action. Patch status is confirmed by the version update note in the description.
Description
sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into the stream. This vulnerability is fixed in 4.0.1.