CVE-2026-121439
Wasmtime 46.0.0 before 48.0.7 and 49.0.0 before 49.0.4 contains a response splitting vulnerability in wasi-http p3 that allows guests to set unvalidated content-length headers. Malicious wasip3 guests can splice an existing body into a new response with an incorrect content-lengt…
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Attention and evidence
Evidence confidence: Insufficient evidence
Hype components
Sources and documents
Score evolution
● Hype ● Reality
━ Hype Score (Perceived) ━ Reality threat priority. Definition changes are not new attacks.
Public exploit evidence
Public exploit entries / repo candidates
Evidence context and dated references
Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs. Published 4 days ago. Exploitation evidence usually takes weeks to show up: a low reality score can mean there is no data yet, not that the flaw is mild.
Evidence in context
- Confidence in exploitation evidence
- Insufficient evidence
- Priority basis
- Exploitation in attacks unconfirmed; CVSS 5.3; EPSS 0.2%
- Attention, last 30 days
- 0 distinct story titles; 0 press documents; 0 publisher domains.
- Technical potential
- network access, no prior privileges, no user interaction.
- Observed activity
- No exploitation observation is recorded.
- Known scale
- Not quantified.
- Evidence confidence basis
- Insufficient evidence
Score evaluated: 2026-11-05 13:59:56.876805+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z