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Exploited in the wildServers & business softwareWork IT

CVE-2015-5477 ISC BIND: software flaw

In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.

Confirmed exploited by CISA on · US federal patch deadline Oct 11, 2026

What to do

  1. Install ISC's security update for BIND. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Read ISC's advisory ↗

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.

The details

Official name
ISC BIND Data Processing Errors Vulnerability
Product
ISC BIND
CISA description
ISC BIND contains a data processing errors vulnerability that could allow remote attackers to cause a denial of service via TKEY queries.
Type of flaw
Software flaw (CWE-19)
Confirmed exploited
Oct 8, 2026
US federal patch deadline
Oct 11, 2026

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Answering about CVE-2015-5477 ·

Questions about CVE-2015-5477

Is CVE-2015-5477 being exploited?

Yes. CISA added CVE-2015-5477 to its Known Exploited Vulnerabilities catalog on Oct 8, 2026, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2015-5477?

Install ISC's security update for BIND. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.

Am I affected by CVE-2015-5477?

Only if you use ISC BIND. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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