cert-manager-controller DoS via Specially Crafted DNS Response
cve-program · CVE-2026-25518
Publishedcert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
Read the publisher's advisoryeuvd · EUVD-2026-5341
Publishedcert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
Read the publisher's advisorynvd · CVE-2026-25518
Publishedcert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
Read the publisher's advisoryosv · GHSA-gx3x-vq4p-mhhv
Published### Impact The cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in Denial of Service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. ### Patches The vulnerability was introduced in cert-manager v1.18.0 and has been patched in cert-manager v1.19.3 and v1.18.5, which are the supported minor releases at the time of publishing. cert-manager versions prior to v1.18.0 are unaffected. ### Workarounds - Using DNS-over-HTTPS reduces the risk of DNS traffic being intercepted and modified. - Note that DNS-over-HTTPS does *not* prevent the risk of an attacker-controlled authoritative DNS server. ### Resources - Fix for cert-manager 1.18: https://github.com/cert-manager/cert-manager/pull/8467 - Fix for cert-manager 1.19: https://github.com/cert-manager/cert-manager/pull/8468 - Fix for master branch: https://github.com/cert-manager/cert-manager/pull/8469 ### Credits Huge thanks to Oleh Konko (@1seal) for reporting the issue, providing a detailed PoC and an initial patch!
Read the publisher's advisoryosv · GO-2026-4399
PublishedDoS in cert-manager-controller via Specially Crafted DNS Response in github.com/cert-manager/cert-manager
Read the publisher's advisoryAffected versions, risk and source history
Exploitation and risk
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cve-program · CVE-2026-25518
Publishedcert-manager-controller DoS via Specially Crafted DNS Response
cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
- Source published
- 4 Feb 2026 21:18:06 UTC
- Source modified
- 5 Feb 2026 14:31:52 UTC
- Saved here
- 23 Oct 2026 15:48:27 UTC
- Source terms
- CVE Program Terms of Use
Original source record · Cite this exact observation · Complete original publisher JSON
Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
euvd · EUVD-2026-5341
Publishedcert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to bef…
cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
Additional publisher context
EUVD source date text has no stated timezone and is retained without inventing a UTC instant. Related bulletin membership is not an alias, common cause or applicability claim. A missing vector with a zero score is treated as unrated. Complete vendor/product and underlying source evidence remains in the original JSON.
Original publisher date fields
datePublished: Feb 4, 2026, 9:18:06 PM
dateUpdated: Feb 5, 2026, 2:31:52 PM
1 related source bulletins · separate from aliases
WID-SEC-W-2026-1007: IBM App Connect Enterprise: Mehrere Schwachstellen
CVE-2025-14550 · CVE-2025-14831 · CVE-2025-15281 · CVE-2025-15366 · CVE-2025-15367 · CVE-2025-15599 · CVE-2025-55130 · CVE-2025-55131 · CVE-2025-55132 · CVE-2025-59465 · CVE-2025-59466 · CVE-2025-68470 · CVE-2025-9820 · CVE-2026-0540 · CVE-2026-0861 · CVE-2026-0915 · CVE-2026-0980 · CVE-2026-1207 · CVE-2026-1285 · CVE-2026-1287 · CVE-2026-1299 · CVE-2026-1312 · CVE-2026-1530 · CVE-2026-1531 · CVE-2026-1961 · CVE-2026-21637 · CVE-2026-22029 · CVE-2026-23490 · CVE-2026-2436 · CVE-2026-25518 · CVE-2026-27137 · CVE-2026-27138 · CVE-2026-27959 · CVE-2026-29063 · CVE-2026-29087 · CVE-2026-30922 · CVE-2026-3632 · CVE-2026-3633 · CVE-2026-3634 · CVE-2026-3731 · CVE-2026-4271 · CVE-2026-4324 · CVE-2026-5119
- Source published
- Feb 4, 2026, 9:18:06 PM (timezone not stated)
- Source modified
- Feb 5, 2026, 2:31:52 PM (timezone not stated)
- Saved here
- 15 Nov 2026 07:40:35 UTC
- Source terms
- ENISA EUVD · source terms and attribution apply
Original source record · Cite this exact observation · Complete original publisher JSON
Source: euvd · ENISA EUVD · source terms and attribution apply. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
EUVD CVSS 3.1 · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd · CVE-2026-25518
Publishedcert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to bef…
cert-manager adds certificates and certificate issuers as resource types in Kubernetes clusters, and simplifies the process of obtaining, renewing and using those certificates. In versions from 1.18.0 to before 1.18.5 and from 1.19.0 to before 1.19.3, the cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in denial‑of‑service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. This issue has been patched in versions 1.18.5 and 1.19.3.
Additional publisher context
NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON.
Source analysis status: Analyzed
Weakness classifications: CWE-129 · CWE-704
Original publisher date fields
published: 2026-02-04T22:15:58.990
lastModified: 2026-06-17T10:24:46.760
1 source CPE criteria · context only
- cpe:2.3:a:cert-manager:cert-manager:*:*:*:*:*:*:*:*
The original JSON retains the logical configuration operators, exclusions and version bounds.
- Source published
- 4 Feb 2026 22:15:58 UTC
- Source modified
- 17 Jun 2026 10:24:46 UTC
- Saved here
- 25 Oct 2026 06:17:16 UTC
- Source terms
- NIST NVD usage terms; underlying source attribution retained
Original source record · Cite this exact observation · Complete original publisher JSON
Source: nvd · NIST NVD usage terms; underlying source attribution retained. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · [email protected] · Secondary · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 3.1 · [email protected] · Primary · 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
osv · GHSA-gx3x-vq4p-mhhv
Publishedcert-manager-controller DoS via Specially Crafted DNS Response
### Impact The cert-manager-controller performs DNS lookups during ACME DNS-01 processing (for zone discovery and propagation self-checks). By default, these lookups use standard unencrypted DNS. An attacker who can intercept and modify DNS traffic from the cert-manager-controller pod can insert a crafted entry into cert-manager's DNS cache. Accessing this entry will trigger a panic, resulting in Denial of Service (DoS) of the cert-manager controller. The issue can also be exploited if the authoritative DNS server for the domain being validated is controlled by a malicious actor. ### Patches The vulnerability was introduced in cert-manager v1.18.0 and has been patched in cert-manager v1.19.3 and v1.18.5, which are the supported minor releases at the time of publishing. cert-manager versions prior to v1.18.0 are unaffected. ### Workarounds - Using DNS-over-HTTPS reduces the risk of DNS traffic being intercepted and modified. - Note that DNS-over-HTTPS does *not* prevent the risk of an attacker-controlled authoritative DNS server. ### Resources - Fix for cert-manager 1.18: https://github.com/cert-manager/cert-manager/pull/8467 - Fix for cert-manager 1.19: https://github.com/cert-manager/cert-manager/pull/8468 - Fix for master branch: https://github.com/cert-manager/cert-manager/pull/8469 ### Credits Huge thanks to Oleh Konko (@1seal) for reporting the issue, providing a detailed PoC and an initial patch!
- Source published
- 2 Feb 2026 22:11:06 UTC
- Source modified
- 10 Sep 2026 03:50:35 UTC
- Saved here
- 24 Oct 2026 13:19:41 UTC
- Source terms
- GitHub Advisory Database · CC-BY-4.0
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · GitHub Advisory Database · CC-BY-4.0. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Publisher rating · MODERATE
osv · GO-2026-4399
PublishedDoS in cert-manager-controller via Specially Crafted DNS Response in github.com/cert-manager/cert-manager
DoS in cert-manager-controller via Specially Crafted DNS Response in github.com/cert-manager/cert-manager
- Source published
- 19 Feb 2026 17:28:55 UTC
- Source modified
- 16 Mar 2026 14:55:08 UTC
- Saved here
- 24 Oct 2026 13:19:41 UTC
- Source terms
- OSV · upstream source license applies
Original source record · Cite this exact observation · Complete original publisher JSON
Source: osv · OSV · upstream source license applies. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.