Answer in brief
CVE-2025-4035 records a Medium severity (CVSS 4.3) vulnerability in Libsoup: cookie domain validation bypass via uppercase characters in libsoup. The current sources do not mark it as known exploited. The current feed maps Red Hat/libsoup (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 4.3. 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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Red Hat/libsoupgeneric | * | Not reported |
Published upstream
Apr 29, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jun 30, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 25, 2026
A flaw was found in libsoup. When handling cookies, libsoup clients mistakenly allow cookies to be set for public suffix domains if the domain contains at least two components and includes an uppercase character. This bypasses public suffix protections and could allow a malicious website to set cookies for domains it does not own, potentially leading to integrity issues such as session fixation.
Quoted source text, attributed separately from HOL analysis.