cve-2026-11721-els_os-ubuntu20.04els
csaf_tuxcare
Description
This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.
Timeline
- Published
- 2026-07-22 15:16 UTC
- Last Modified
- 2026-10-15
CVSS Details
CVSS details not available.
Affected Products
No product information available.
Weaknesses (CWE)
References
No references available.
Linked Vulnerabilities
No linked vulnerabilities found.
{
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"distribution": {
"text": "TuxCare License Agreement",
"tlp": {
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"url": "https://www.first.org/tlp/"
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"lang": "en",
"notes": [
{
"category": "legal_disclaimer",
"text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
"title": "Terms of Use"
}
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"publisher": {
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"contact_details": "https://tuxcare.com/contact/",
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"title": "Security update on CVE-2026-11721",
"tracking": {
"current_release_date": "2026-10-15T19:15:31Z",
"generator": {
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"engine": {
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"id": "CVE-2026-11721-ELS_OS-UBUNTU20.04ELS",
"initial_release_date": "2026-07-22T15:16:00Z",
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"cwe": {
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"name": "Improper Validation of Specified Quantity in Input"
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"notes": [
{
"category": "description",
"text": "It is possible for an attacker's zone to respond to a query with an RRSIG that has a smaller number of labels than the zone in which the RRSIG is contained. This causes `named` to produce a wildcard name for a zone that is shorter than the attacker's zone, which can result in cache poisoning. For this attack to have any effect, the resolver under attack must have set `synth-from-dnssec yes;` (which is the default).\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.",
"title": "Vulnerability description"
}
],
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"summary": "https://downloads.isc.org/isc/bind9/9.20.26",
"url": "https://downloads.isc.org/isc/bind9/9.20.26"
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"summary": "https://downloads.isc.org/isc/bind9/9.21.24",
"url": "https://downloads.isc.org/isc/bind9/9.21.24"
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{
"category": "external",
"summary": "https://kb.isc.org/docs/cve-2026-11721",
"url": "https://kb.isc.org/docs/cve-2026-11721"
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],
"release_date": "2026-07-22T15:16:00Z",
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{
"category": "no_fix_planned",
"date": "2026-10-13T10:58:28.591921Z",
"details": "This issue only applies when BIND is acting as a validating recursive resolver with synth-from-dnssec enabled; authoritative-only deployments or systems not providing recursion are unaffected. The attack is high complexity and results only in low confidentiality/integrity impact with no availability effect (CVSS 4.8), which limits practical risk. Given these narrow preconditions and the constrained impact, it can be safely deprioritized relative to vulnerabilities enabling direct compromise or broader disruption.",
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