CVE-2026-15709: Soupwebsocketextensiondeflate: libsoup: libsoup: websocket permessage-deflate unbounded decompression remote denial of service
CSIRTS triage
- What
- There is a remote denial of service vulnerability due to unbounded decompression in websocket permessage-deflate.
- Who is affected
- Deployments of libsoup are affected.
- Urgency
- Remediation is urgent due to the high severity of the vulnerability.
- Action
- Upgrade to a patched version of libsoup.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-15709
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-157090.55% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 43% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-15709 | coverage & exploitation status | NVD · CVE.org |
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