CVE-2026-43968: CR Injection in SSE Encoder Enables Event Splitting via cow_sse:event/1
ninenines · cowlib
Fixed in 2.16.1 · Affected: ninenines cowlib before 2.16.1 · Exploitation: unlikely (under 1%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 18% of scored CVEs
DescriptionCVE.org
Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows SSE event splitting and injection via unvalidated field values. cow_sse:event/1 in cowlib guards the id and event fields against \n but not against bare \r, and the internal prefix_lines/2 function used for data and comment fields splits only on \n. Because the SSE specification requires decoders to treat \r\n, \r, and \n as equivalent line terminators, an attacker who controls any of these fields can inject additional SSE lines and forge a complete event with an arbitrary event type and data payload on the receiving end. In typical deployments where browser EventSource clients or other SSE consumers dispatch on event.type and render event.data, this enables event splitting, client-side logic manipulation, and stored-XSS-equivalent behaviour when event data is inserted into the DOM. This issue affects cowlib from 2.6.0 before 2.16.1.
Affected products2
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- ninenines · cowlibfrom 2.6.0 before 2.16.1
- ninenines · cowlibVersions not stated
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CoverageNo articles yet
No CyberSIXT article names CVE-2026-43968 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.