CVE catalog

CVE-2026-96405

unbound: CVE-2026-96405

Severity: Medium · CVSS 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Published: Oct 21, 2026, 9:17:08 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.25% · Oct 25, 2026

NLnet Labs Unbound up to and including version 1.26.1 limits compression-pointer traversal for each individual domain-name operation but has no aggregate inbound decompression-work budget. Many chained compression pointers in a message results in a lot of CPU usage following them. A malicious actor with recursive-query access and control of an ordinarily delegated authority that serves specially crafted replies can exploit the vulnerability and degrade Unbound's general performance.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	unbound	sid	`1.26.2-1`	fixed
Debian	unbound	forky	`1.26.2-1`	fixed
Debian	unbound	trixie	`1.22.0-2+deb13u3`	vulnerable
Debian	unbound	trixie-security	`1.26.2-0+deb13u1`	fixed
Debian	unbound	bookworm	`1.17.1-2+deb12u4`	vulnerable
Debian	unbound	bookworm-security	`1.17.1-2+deb12u3`	vulnerable
Ubuntu	unbound	pro	`1.9.0-2ubuntu1`	vulnerable
Ubuntu	unbound	pro	`1.9.0-2ubuntu2`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.1`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.2`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.3`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.4`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.5`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.6`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.8`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.9`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.11`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.11+esm1`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.11+esm2`	vulnerable
Ubuntu	unbound	pro	`1.9.4-2ubuntu1.11+esm3`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu1`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu3`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.1`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.2`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.3`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.4`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.5`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.7`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.8`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.10`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.11`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.12`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.13`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.14`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.15`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.16`	vulnerable
Ubuntu	unbound	22.04	`1.13.1-1ubuntu5.17`	vulnerable
Ubuntu	unbound	24.04	`1.17.1-2`	vulnerable
Ubuntu	unbound	24.04	`1.18.0-2ubuntu1`	vulnerable
Ubuntu	unbound	24.04	`1.18.0-2ubuntu2`	vulnerable
Ubuntu	unbound	24.04	`1.19.1-1ubuntu1`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu1`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.1`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.2`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.3`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.4`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.5`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.6`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.7`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.8`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.9`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.10`	vulnerable
Ubuntu	unbound	24.04	`1.19.2-1ubuntu3.12`	vulnerable
Ubuntu	unbound	26.10	`1.24.2-1ubuntu2`	vulnerable
Ubuntu	unbound	26.10	`1.25.1-1ubuntu1`	vulnerable
Ubuntu	unbound	26.10	`1.25.1-1ubuntu3`	vulnerable
Ubuntu	unbound	26.04	`1.22.0-2ubuntu2`	vulnerable
Ubuntu	unbound	26.04	`1.22.0-2ubuntu4`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu1`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu2`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu2.1`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu2.2`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu2.3`	vulnerable
Ubuntu	unbound	26.04	`1.24.2-1ubuntu2.4`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	unbound	source	sid	`1.26.2-1`	not yet assigned	Not reported	Not reported
Debian	unbound	source	forky	`1.26.2-1`	not yet assigned	Not reported	Not reported
Debian	unbound	source	trixie	`1.26.2-0+deb13u1`	not yet assigned	Not reported	Not reported
Debian	unbound	source	bookworm	`(unfixed)`	not yet assigned	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libunbound8]Affected
Source package: [unbound]
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
[libunbound-dev]Affected
Source package: [unbound]
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
[python3-unbound]Affected
Source package: [unbound]
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
[unbound]Affected
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
[unbound-anchor]Affected
Source package: [unbound]
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
[unbound-host]Affected
Source package: [unbound]
Details (4)
- 1.17.1-2+deb12u4 · amd64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u4 · arm64 · bookworm
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · amd64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12
- 1.17.1-2+deb12u3 · arm64 · bookworm-security
  Affected
  dsa · unbound · debian · bookworm; dsa · unbound · debian · 12

[Debian 13 (Trixie)]

[libunbound8]Affected
Source package: [unbound]
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
[libunbound-dev]Affected
Source package: [unbound]
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
[python3-unbound]Affected
Source package: [unbound]
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
[unbound]Affected
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
[unbound-anchor]Affected
Source package: [unbound]
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
[unbound-host]Affected
Source package: [unbound]
Details (6)
- 1.22.0-2+deb13u3 · amd64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.22.0-2+deb13u3 · arm64 · trixie-security
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.1-0+deb13u1 · amd64 · trixie-security · Historical version
  Affected · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13
- 1.26.2-0+deb13u1 · amd64 · trixie-security
  Fixed · Fixed: 1.26.2-0+deb13u1
  dsa · unbound · debian · 13

Observed: Oct 27, 2026, 4:08:10 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database]