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major vulnerability· requires attention

Affects OpenSSL's DTLS implementation — a widely deployed crypto library; can cause data disclosure or DoS across many applications.

Cryptography

CVE-2026-84782

8.2
High
EPSS n/aPatch availableSep 30, 2026

OpenSSL DTLS retransmission bug can leak heap data or crash (DoS).

common questions

Is CVE-2026-84782 being exploited?

Not confirmed. CVE-2026-84782 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked.

How severe is CVE-2026-84782?

CVE-2026-84782 is rated High with a CVSS score of 8.2. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.

Is there a patch for CVE-2026-84782?

Yes. A fix has been recorded for CVE-2026-84782. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-84782 affect?

CVE-2026-84782 affects OpenSSL (DTLS module), Applications using OpenSSL DTLS (VPNs, VoIP, IoT). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-84782?

Upgrade OpenSSL to the fixed release and restart DTLS-enabled services.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
OpenSSL (DTLS module)Applications using OpenSSL DTLS (VPNs, VoIP, IoT)
impact

DTLS retransmission OOB read can expose heap memory to a remote peer or crash the process, enabling data disclosure or DoS.

action required

Immediate action required

affected versions
OpenSSL OpenSSL
  • affected>= 4.0.0 and < 4.0.3
  • affected>= 3.6.0 and < 3.6.5
  • affected>= 3.5.0 and < 3.5.9
  • affected>= 3.4.0 and < 3.4.8
  • affected>= 3.0.0 and < 3.0.23
  • affected>= 1.1.1 and < 1.1.1zj
  • affected>= 1.0.2 and < 1.0.2zs

As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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