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Public proof of conceptFix available

CVE-2026-2291

CVE-2026-2291

A public proof of concept exists; no exploitation attested.

  • Published2026-05-11

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS.

Timeline

dates in UTC
  1. 2026-05-1118:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-2291?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-2291?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • dnsmasqAlmaLinux:10all versions · fixed in 2.90-7.el10_2and 1 other package
  • dnsmasqAlmaLinux:9all versions · fixed in 2.85-18.el9_8.1and 1 other package
  • dnsmasqAlmaLinux:8all versions · fixed in 2.79-36.el8_10and 1 other package

Vendor advisories

  • CVE-2026-2291 Red Hat Product Security88 products fixed · 7 known affected

    dnsmasq: dnsmasq: heap buffer overflow in cache via NAME_ESCAPE expansion

    dnsmasq as a component of Red Hat Enterprise Linux 6 · dnsmasq-utils as a component of Red Hat Enterprise Linux 6 · dnsmasq.src as a component of Red Hat Enterprise Linux 6 · +4 more

  • RHSA-2026:54553 Red Hat Product Security4 products fixed

    Red Hat Security Advisory: OpenShift Container Platform 4.19.43 bug fix and security update

  • RHSA-2026:34508 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: dnsmasq security update

  • RHSA-2026:20589 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: dnsmasq security update

  • RHSA-2026:19373 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: dnsmasq security update

  • RHSA-2026:19158 Red Hat Product Security21 products fixed

    Red Hat Security Advisory: dnsmasq security update

Full record on NVD

Fix

  1. Vendor fix Red Hat Product Security RHSA-2026:54553 · 4 productsFor OpenShift Container Platform 4.19 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.…
  2. Vendor fix Red Hat Product Security RHSA-2026:34508 · 21 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
  3. No fix available, says the vendor Red Hat Product Security CVE-2026-2291 · 4 productsAffected
  4. No fix planned, says the vendor Red Hat Product Security CVE-2026-2291 · 3 productsOut of support scope

Detection

read 2026-10-23 19:25 UTC
Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
1 repository, unverifiedJianrongXiao-Linksys/dnsmasq-cve-2026
PoC-in-GitHub

Sources

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2026-05-11
Last Modified
2026-07-20
NVD status
Awaiting Analysis
MSRC Title
CVE-2026-2291

Frequently asked questions

What is CVE-2026-2291?

dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing an attacker to inject false DNS cache entries, which could result in DNS lookups to redirect to an attacker-controlled IP address, or to cause a DoS.

Is CVE-2026-2291 actively exploited?

Active exploitation of CVE-2026-2291 has not been confirmed. Its EPSS score was 0.6% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-2291?

CVE-2026-2291 has a CVSS v3 base score of 7.3 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.

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