CVE-2026-4926

path-to-regexp vulnerable to Denial of Service via sequential optional groups

CVSS 3.1 7.5 HIGHEUVD CVSS 3.1 7.5 CVSS 3.1 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary 7.5 HIGHCVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary 7.5 HIGHCVSS_V3 Publisher rating HIGHFixed by path-to-regexp 8.4.0KEV status unknown

Original advisory

cve-program · CVE-2026-4926

Published

Impact: A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. Patches: Fixed in version 8.4.0. Workarounds: Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.

Read the publisher's advisory

euvd · EUVD-2026-16324

Published

Read the publisher's advisory

nvd · CVE-2026-4926

Published

Read the publisher's advisory

osv · GHSA-j3q9-mxjg-w52f

Published

### Impact A bad regular expression is generated any time you have multiple sequential optional groups (curly brace syntax), such as `{a}{b}{c}:z`. The generated regex grows exponentially with the number of groups, causing denial of service. ### Patches Fixed in version 8.4.0. ### Workarounds Limit the number of sequential optional groups in route patterns. Avoid passing user-controlled input as route patterns.

Read the publisher's advisory

Affected versions, risk and source history

Exploitation and risk

Source status

CISA KEV lists vulnerabilities known to be exploited. FIRST EPSS estimates the likelihood of exploitation in the next 30 days. An unavailable score does not mean zero risk.

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This view includes predictions for CVE identifiers explicitly listed in public NuGet advisories. Microsoft release pages have their own prediction coverage. Check source status for the scope and latest checks.

No exploitation or prediction data is available here for these CVEs. This does not mean they are safe or unlikely to be exploited.

cve-program · CVE-2026-4926

Published

path-to-regexp vulnerable to Denial of Service via sequential optional groups

Source published: 26 Mar 2026 18:59:38 UTC
Source modified: 17 Sep 2026 12:04:38 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 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

euvd · EUVD-2026-16324

Published

Impact:

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: Mar 26, 2026, 6:59:38 PM

dateUpdated: Sep 17, 2026, 12:04:38 PM

20 related source bulletins · separate from aliases

RHSA-2026:13545: Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update

CVE-2025-68121 · CVE-2025-69227 · CVE-2025-69228 · CVE-2026-0598 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-6266 · CVE-2026-12382 · CVE-2026-23490 · CVE-2026-24049 · CVE-2026-25679 · CVE-2026-26007 · CVE-2026-27137 · CVE-2026-27459 · CVE-2026-27606 · CVE-2026-29074 · CVE-2026-30922 · CVE-2026-31812 · CVE-2026-32274 · CVE-2026-32280 · CVE-2026-32597 · CVE-2026-33154 · CVE-2026-33810 · CVE-2026-35029 · CVE-2026-35030

RHSA-2026:19410: Red Hat Security Advisory: MTV RHEL9 Images

CVE-2026-4598 · CVE-2026-4599 · CVE-2026-4600 · CVE-2026-4601 · CVE-2026-4602 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-29063

RHSA-2026:50300: Red Hat Security Advisory: Migration Toolkit for Applications

CVE-2026-4926 · CVE-2026-12143 · CVE-2026-13149 · CVE-2026-25681 · CVE-2026-26996 · CVE-2026-27136 · CVE-2026-27904 · CVE-2026-33811 · CVE-2026-39820 · CVE-2026-39821 · CVE-2026-40895 · CVE-2026-42039 · CVE-2026-42041 · CVE-2026-42044 · CVE-2026-42264 · CVE-2026-42342 · CVE-2026-42499 · CVE-2026-42504 · CVE-2026-44486 · CVE-2026-44487 · CVE-2026-44488 · CVE-2026-44492 · CVE-2026-44494 · CVE-2026-44495 · CVE-2026-44496 · CVE-2026-55603

WID-SEC-W-2026-1407: IBM App Connect Enterprise Certified Container: Mehrere Schwachstellen

CVE-2026-26013 · CVE-2026-27142 · CVE-2026-28277 · CVE-2026-28684 · CVE-2026-32288 · CVE-2026-33151 · CVE-2026-33349 · CVE-2026-33532 · CVE-2026-33891 · CVE-2026-33894 · CVE-2026-33895 · CVE-2026-33896 · CVE-2026-33916 · CVE-2026-34601 · CVE-2026-35469 · CVE-2026-39406 · CVE-2026-39407 · CVE-2026-39408 · CVE-2026-39409 · CVE-2026-39410 · CVE-2026-39983 · CVE-2026-40175 · CVE-2026-40347 · CVE-2026-40895 · CVE-2026-41238 · CVE-2026-41239 · CVE-2026-41240 · CVE-2026-4923 · CVE-2026-4926

RHSA-2026:10175: Red Hat Security Advisory: Red Hat OpenShift Dev Spaces 3.27.1 Release.

CVE-2025-61728 · CVE-2025-62718 · CVE-2026-2332 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-22731 · CVE-2026-25679 · CVE-2026-26999 · CVE-2026-27137 · CVE-2026-27606 · CVE-2026-29054 · CVE-2026-32305 · CVE-2026-32695 · CVE-2026-33186 · CVE-2026-33433 · CVE-2026-33805 · CVE-2026-33870 · CVE-2026-33871 · CVE-2026-33937 · CVE-2026-33938 · CVE-2026-33939 · CVE-2026-33940 · CVE-2026-33941 · CVE-2026-34986 · CVE-2026-40175

RHSA-2026:13826: Red Hat Security Advisory: Red Hat Developer Hub 1.9.4 release.

CVE-2025-62718 · CVE-2025-69534 · CVE-2026-1525 · CVE-2026-1526 · CVE-2026-1528 · CVE-2026-2229 · CVE-2026-3118 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-27601 · CVE-2026-27904 · CVE-2026-29063 · CVE-2026-29074 · CVE-2026-29186 · CVE-2026-32141 · CVE-2026-32280 · CVE-2026-32282 · CVE-2026-33228 · CVE-2026-33891 · CVE-2026-33894 · CVE-2026-33895 · CVE-2026-33896 · CVE-2026-39983 · CVE-2026-40175 · CVE-2026-40895

RHSA-2026:10153: Red Hat Security Advisory: RHTAS 1.3.4 - Red Hat Trusted Artifact Signer Release

CVE-2026-4926 · CVE-2026-33186 · CVE-2026-40175

RHSA-2026:24762: Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Product Security and Bug Fix Update

CVE-2026-4800 · CVE-2026-4926 · CVE-2026-7246 · CVE-2026-30922 · CVE-2026-32280 · CVE-2026-32282 · CVE-2026-32283 · CVE-2026-33891 · CVE-2026-39363 · CVE-2026-39892 · CVE-2026-40175 · CVE-2026-40192

RHSA-2026:40118: Red Hat Security Advisory: Red Hat Edge Manager Version 1.1.3 Security Update

CVE-2025-13465 · CVE-2025-61729 · CVE-2025-68121 · CVE-2025-69873 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-6322 · CVE-2026-13676 · CVE-2026-22029 · CVE-2026-25679 · CVE-2026-29063 · CVE-2026-32141 · CVE-2026-32280 · CVE-2026-32281 · CVE-2026-32282 · CVE-2026-33186 · CVE-2026-33810 · CVE-2026-33811 · CVE-2026-33816 · CVE-2026-39821 · CVE-2026-39828 · CVE-2026-39829 · CVE-2026-39830 · CVE-2026-39832 · CVE-2026-39835 · CVE-2026-42151 · CVE-2026-42154 · CVE-2026-42508 · CVE-2026-46595

RHSA-2026:9742: Red Hat Security Advisory: Red Hat Developer Hub 1.8.6 release.

CVE-2025-62718 · CVE-2025-69534 · CVE-2025-69873 · CVE-2026-1525 · CVE-2026-1526 · CVE-2026-1528 · CVE-2026-2229 · CVE-2026-3118 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-25679 · CVE-2026-26996 · CVE-2026-27601 · CVE-2026-27904 · CVE-2026-29063 · CVE-2026-29074 · CVE-2026-29186 · CVE-2026-32141 · CVE-2026-33036 · CVE-2026-33228 · CVE-2026-33891 · CVE-2026-33894 · CVE-2026-33895 · CVE-2026-33896 · CVE-2026-39983 · CVE-2026-40175

RHSA-2026:19409: Red Hat Security Advisory: MTV RHEL9 Images

CVE-2026-4598 · CVE-2026-4599 · CVE-2026-4600 · CVE-2026-4601 · CVE-2026-4602 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-29063

RHSA-2026:40945: Red Hat Security Advisory: Red Hat Edge Manager Version 1.1.3 Security Update

WID-SEC-W-2026-3046: IBM Concert: Mehrere Schwachstellen

CVE-2019-19921 · CVE-2021-23337 · CVE-2024-3651 · CVE-2024-39338 · CVE-2024-45590 · CVE-2025-13465 · CVE-2025-15284 · CVE-2025-15599 · CVE-2025-22874 · CVE-2025-47273 · CVE-2025-47907 · CVE-2025-52881 · CVE-2025-53643 · CVE-2025-55184 · CVE-2025-58056 · CVE-2025-58188 · CVE-2025-58189 · CVE-2025-61723 · CVE-2025-61730 · CVE-2025-64649 · CVE-2025-64756 · CVE-2025-67221 · CVE-2025-68121 · CVE-2025-68146 · CVE-2026-0540 · CVE-2026-2327 · CVE-2026-23490 · CVE-2026-23897 · CVE-2026-2391 · CVE-2026-23949 · CVE-2026-24486 · CVE-2026-25528 · CVE-2026-25547 · CVE-2026-25639 · CVE-2026-25990 · CVE-2026-26007 · CVE-2026-26019 · CVE-2026-26996 · CVE-2026-27142 · CVE-2026-27212 · CVE-2026-27699 · CVE-2026-27903 · CVE-2026-27904 · CVE-2026-28684 · CVE-2026-29063 · CVE-2026-29181 · CVE-2026-2950 · CVE-2026-31808 · CVE-2026-31900 · CVE-2026-32274 · CVE-2026-32288 · CVE-2026-32597 · CVE-2026-32630 · CVE-2026-32887 · CVE-2026-32952 · CVE-2026-33186 · CVE-2026-33532 · CVE-2026-33750 · CVE-2026-33814 · CVE-2026-33816 · CVE-2026-33916 · CVE-2026-34043 · CVE-2026-34073 · CVE-2026-34077 · CVE-2026-3520 · CVE-2026-35469 · CVE-2026-35515 · CVE-2026-3627 · CVE-2026-39823 · CVE-2026-39825 · CVE-2026-39826 · CVE-2026-39892 · CVE-2026-39984 · CVE-2026-40175 · CVE-2026-40179 · CVE-2026-40181 · CVE-2026-40190 · CVE-2026-40347 · CVE-2026-41066 · CVE-2026-41182 · CVE-2026-41238 · CVE-2026-41239 · CVE-2026-41240 · CVE-2026-41305 · CVE-2026-41324 · CVE-2026-41425 · CVE-2026-41481 · CVE-2026-41488 · CVE-2026-41602 · CVE-2026-41636 · CVE-2026-42151 · CVE-2026-42154 · CVE-2026-42198 · CVE-2026-42211 · CVE-2026-42338 · CVE-2026-42342 · CVE-2026-42561 · CVE-2026-42577 · CVE-2026-43870 · CVE-2026-44405 · CVE-2026-44431 · CVE-2026-44432 · CVE-2026-44486 · CVE-2026-44487 · CVE-2026-44488 · CVE-2026-44492 · CVE-2026-44494 · CVE-2026-44496 · CVE-2026-44728 · CVE-2026-4539 · CVE-2026-45409 · CVE-2026-45736 · CVE-2026-46625 · CVE-2026-4800 · CVE-2026-4923 · CVE-2026-4926 · CVE-2026-7246 · CVE-2026-8723

RHSA-2026:17789: Red Hat Security Advisory: Red Hat build of Cryostat 4.2.0: new RHEL 9 container image security update

CVE-2026-1002 · CVE-2026-1525 · CVE-2026-1526 · CVE-2026-1528 · CVE-2026-2229 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-33186 · CVE-2026-33813 · CVE-2026-33815 · CVE-2026-33816 · CVE-2026-33870 · CVE-2026-33871 · CVE-2026-34986 · CVE-2026-39852 · CVE-2026-40895

RHSA-2026:65126: Red Hat Security Advisory: RHOAI 2.25.11 - Red Hat OpenShift AI

CVE-2025-61729 · CVE-2025-67030 · CVE-2026-4926 · CVE-2026-6734 · CVE-2026-9563 · CVE-2026-9697 · CVE-2026-12151 · CVE-2026-12243 · CVE-2026-13149 · CVE-2026-15075 · CVE-2026-15154 · CVE-2026-15378 · CVE-2026-15581 · CVE-2026-16745 · CVE-2026-18608 · CVE-2026-18611 · CVE-2026-18617 · CVE-2026-18620 · CVE-2026-18621 · CVE-2026-25681 · CVE-2026-26996 · CVE-2026-27136 · CVE-2026-27904 · CVE-2026-30922 · CVE-2026-32283 · CVE-2026-33231 · CVE-2026-33810 · CVE-2026-33811 · CVE-2026-33814 · CVE-2026-33870 · CVE-2026-33871 · CVE-2026-34445 · CVE-2026-35536 · CVE-2026-39821 · CVE-2026-39829 · CVE-2026-39835 · CVE-2026-40171 · CVE-2026-40192 · CVE-2026-40895 · CVE-2026-41178 · CVE-2026-42027 · CVE-2026-42215 · CVE-2026-42284 · CVE-2026-42338 · CVE-2026-42502 · CVE-2026-42508 · CVE-2026-42578 · CVE-2026-42579 · CVE-2026-42581 · CVE-2026-42583 · CVE-2026-42584 · CVE-2026-42587 · CVE-2026-44240 · CVE-2026-44244 · CVE-2026-44249 · CVE-2026-44431 · CVE-2026-44893 · CVE-2026-45112 · CVE-2026-45416 · CVE-2026-45623 · CVE-2026-45674 · CVE-2026-45736 · CVE-2026-45819 · CVE-2026-47691 · CVE-2026-48043 · CVE-2026-48059 · CVE-2026-48586 · CVE-2026-48779 · CVE-2026-49978 · CVE-2026-50010 · CVE-2026-50193 · CVE-2026-53550 · CVE-2026-54293 · CVE-2026-54512 · CVE-2026-55685 · CVE-2026-55831 · CVE-2026-55833 · CVE-2026-55851 · CVE-2026-56745 · CVE-2026-56746 · CVE-2026-56819 · CVE-2026-56853 · CVE-2026-56858 · CVE-2026-56859 · CVE-2026-56860 · CVE-2026-56862 · CVE-2026-59869 · CVE-2026-59873 · CVE-2026-59874 · CVE-2026-59885 · CVE-2026-59899 · CVE-2026-66036 · CVE-2026-66039 · CVE-2026-67313 · CVE-2026-67320 · CVE-2026-67322 · CVE-2026-67323 · CVE-2026-67324 · CVE-2026-67325 · CVE-2026-68494 · CVE-2026-69112 · CVE-2026-69152 · CVE-2026-69192 · CVE-2026-69243 · CVE-2026-69244 · CVE-2026-71281 · CVE-2026-73088 · CVE-2026-73089 · CVE-2026-73415 · CVE-2026-73417 · CVE-2026-73566 · CVE-2026-73622 · CVE-2026-73623 · CVE-2026-73624 · CVE-2026-73625 · CVE-2026-73627 · CVE-2026-73643

RHSA-2026:24866: Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.6 Container Release Update

CVE-2025-62718 · CVE-2026-4926 · CVE-2026-6321 · CVE-2026-23490 · CVE-2026-28390 · CVE-2026-28684 · CVE-2026-33154 · CVE-2026-39363 · CVE-2026-39364 · CVE-2026-39892 · CVE-2026-40192 · CVE-2026-40217 · CVE-2026-41140 · CVE-2026-48710

RHSA-2026:9385: Red Hat Security Advisory: Red Hat OpenShift distributed tracing platform (Tempo) 3.9.2 release

CVE-2025-68121 · CVE-2026-4645 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-25679 · CVE-2026-27137 · CVE-2026-32280 · CVE-2026-32282 · CVE-2026-32285 · CVE-2026-33186 · CVE-2026-33810 · CVE-2026-34986

RHSA-2026:24761: Red Hat Security Advisory: Red Hat Ansible Automation Platform 2.5 Product Security and Bug Fix Update

CVE-2025-62718 · CVE-2026-4926 · CVE-2026-7246 · CVE-2026-26996 · CVE-2026-27904 · CVE-2026-30922 · CVE-2026-32280 · CVE-2026-32282 · CVE-2026-32283 · CVE-2026-33891 · CVE-2026-33894 · CVE-2026-33895 · CVE-2026-33896 · CVE-2026-39363 · CVE-2026-39892 · CVE-2026-40192

RHSA-2026:10172: Red Hat Security Advisory: RHTAS 1.3.4 - Red Hat Trusted Artifact Signer Release

CVE-2026-4926 · CVE-2026-33186 · CVE-2026-40175

RHSA-2026:36651: Red Hat Security Advisory: Red Hat Edge Manager Version 1.0.3 Security Update

CVE-2025-13465 · CVE-2025-61729 · CVE-2025-68121 · CVE-2025-69873 · CVE-2026-4800 · CVE-2026-4926 · CVE-2026-6322 · CVE-2026-22029 · CVE-2026-25679 · CVE-2026-29063 · CVE-2026-32141 · CVE-2026-32280 · CVE-2026-33186 · CVE-2026-33810 · CVE-2026-33811 · CVE-2026-39821 · CVE-2026-39828 · CVE-2026-39829 · CVE-2026-39830 · CVE-2026-39832 · CVE-2026-39835 · CVE-2026-42151 · CVE-2026-42154 · CVE-2026-42508 · CVE-2026-46595

Source published: Mar 26, 2026, 6:59:38 PM (timezone not stated)
Source modified: Sep 17, 2026, 12:04:38 PM (timezone not stated)
Saved here: 11 Nov 2026 13:03:33 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 · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

nvd · CVE-2026-4926

Published

Impact:

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: Modified

Weakness classifications: CWE-400 · CWE-1333

Original publisher date fields

published: 2026-03-26T19:17:08.387

lastModified: 2026-09-09T13:20:25.320

1 source CPE criteria · context only

cpe:2.3:a:pillarjs:path-to-regexp:*:*:*:*:*:node.js:*:*

The original JSON retains the logical configuration operators, exclusions and version bounds.

Source published: 26 Mar 2026 19:17:08 UTC
Source modified: 9 Sep 2026 13:20:25 UTC
Saved here: 25 Oct 2026 12:17:32 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 · ce714d77-add3-4f53-aff5-83d477b104bb · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS 3.1 · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c · Secondary · 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

osv · GHSA-j3q9-mxjg-w52f

Published

path-to-regexp vulnerable to Denial of Service via sequential optional groups

Source published: 27 Mar 2026 22:23:27 UTC
Source modified: 10 Sep 2026 03:50:39 UTC
Saved here: 24 Oct 2026 13:17:17 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:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Publisher rating · HIGH