Answer in brief
CVE-2026-3633 records a Low severity (CVSS 3.9) vulnerability in Libsoup: libsoup: header and http request injection via crlf injection. The current sources do not mark it as known exploited. The current feed maps Red Hat/libsoup (generic), Red Hat/libsoup3 (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 3.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Red Hat/libsoup (generic), Red Hat/libsoup3 (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Red Hat/libsoupgeneric | * | Not reported |
| Red Hat/libsoup3generic | * | Not reported |
Published upstream
Mar 17, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 3, 2026
A flaw was found in libsoup. A remote attacker, by controlling the method parameter of the `soup_message_new()` function, could inject arbitrary headers and additional request data. This vulnerability, known as CRLF (Carriage Return Line Feed) injection, occurs because the method value is not properly escaped during request line construction, potentially leading to HTTP request injection.
Quoted source text, attributed separately from HOL analysis.