Event Monitor Cyber
EM-20261109-PHTK VulnerabilityHigh severity

AIOHTTP Vulnerability (CVE-2026-123817)

CVE-2026-123817

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Status
Developing

Since : signals keep joining.

First Signal
Nov 09 21:17 UTCC41 Red Hat Security Data
Page Born
Nov 09 22:18 UTCsecond source joined
Last Signal
Nov 09 22:18 UTC28 hours before snapshot
Sources
21 official · 1 research, news or crowd
Open For
27 hoursso far

Life Of This Page

  1. 1
    Born
    A second, independent source names it.
  2. 2
    Developing · Now
    New signals join; severity can move.
  3. 3
    Confirmed
    Not yet
    CISA KEV lists it, or exploitation in the wild is reported.
  4. 4
    Resolved
    Not yet
    Past the fix deadline and 14 days with no new signal.
  5. 5
    Archived
    Not yet
    30 days after resolved. Read only; the link keeps working. Reopens if it comes back.

The ID never changes, and earlier addresses keep working. A correction is logged, never overwritten. If two pages turn out to be one incident, the later one points to the earlier.

Vulnerability Lifecycle

  1. Disclosed: reached
    Nov 09 22:18 UTC
    C6 NVD published
  2. Scored: reached
    Nov 09 22:18 UTC
    CVSS 8.7 · EPSS 0.3%
  3. Exploited: not yet
    Not yet
    No exploitation reported
  4. Advisories: not yet
    Not yet
    None yet
  5. Vendor Response: reached
    Nov 09 21:17 UTC
    C41 published
  6. Resolved: not yet
    Not yet
    After 14 quiet days

Timeline

18:00Nov 1006:00BornC41 Red Hat Security DataC6 NVD CVE API 2.0

Point at a mark to read it. Squares are signals, colored by severity; every one is also listed under Signals.

Signals

  1. CVE-2026-123817 (CVSS 8.7) (opens source in a new tab) AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.4, the WebSocket reader retains one bytes object for each transport read while reassembling an incomplete frame. A malicious… High severityDatabaseC6 NVD CVE API 2.0
  2. Red Hat: CVE-2026-123817 (important) (opens source in a new tab) aiohttp: aiohttp: Denial of Service via memory exhaustion during WebSocket frame reassembly High severityVendorC41 Red Hat Security Data