CVE-2026-73551

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.6%, top 55% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 4 sources updated this week
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 5.3Exploit: None knownExposed: 0

A fix is available — apply it.

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's URL normalization does not recognize dot and dotdot path segments when they carry semicolon parameters. A request such as /user/..;foo=bar/admin is therefore not canonicalized to /admin even when path normalization is enabled. If an upstream interprets the segment according to RFC 3986 while Envoy applies routing or RBAC to the uncollapsed path, a remote client can cause path confusion and bypass path-based security policy. The relevant scope boundary is that the security consequence depends on a downstream/upstream path interpretation mismatch or a path-based Envoy decision. This issue is fixed in versions 1.36.10, 1.37.6, 1.38.4, and 1.39.1.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
29(Track)
EG Risk 29/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation1% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
45%
KEV
Not listed

Published

September 21, 2026

Last Modified

September 23, 2026

Advisory Details (9)

Auto-updated Sep 21, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

Path normalization does not handle dot and dotdot segments with parameters · Advisory · envoyproxy/envoy · GitHub

https://github.com/envoyproxy/envoy/security/advisories/GHSA-2w8w-rfw7-8gg4
github_release Patch Available

v1.39.1

Patch available: envoyproxy/envoy v1.39.1

https://github.com/envoyproxy/envoy/releases/tag/v1.39.1
github_release Patch Available

v1.38.4

Patch available: envoyproxy/envoy v1.38.4

https://github.com/envoyproxy/envoy/releases/tag/v1.38.4
github_release Patch Available

v1.37.6

Patch available: envoyproxy/envoy v1.37.6

https://github.com/envoyproxy/envoy/releases/tag/v1.37.6
github_release Patch Available

v1.36.10

Patch available: envoyproxy/envoy v1.36.10

https://github.com/envoyproxy/envoy/releases/tag/v1.36.10
github_commit

commit f74d1107c4f5 (envoyproxy/envoy)

Fix landed in envoyproxy/envoy commit f74d1107c4f5 — awaiting tagged release

https://github.com/envoyproxy/envoy/commit/f74d1107c4f5c9679b66f7a03a6c5b75ddde1989
github_commit

commit e9d6c329f9a3 (envoyproxy/envoy)

Fix landed in envoyproxy/envoy commit e9d6c329f9a3 — awaiting tagged release

https://github.com/envoyproxy/envoy/commit/e9d6c329f9a3ff19432bf39b60c601df7e3eda33
github_commit

commit d40a68b0a30a (envoyproxy/envoy)

Fix landed in envoyproxy/envoy commit d40a68b0a30a — awaiting tagged release

https://github.com/envoyproxy/envoy/commit/d40a68b0a30a003c4e0a9fd3af637f828b52c37b
github_commit

commit 28b6d60a6d96 (envoyproxy/envoy)

Fix landed in envoyproxy/envoy commit 28b6d60a6d96 — awaiting tagged release

https://github.com/envoyproxy/envoy/commit/28b6d60a6d96edeece121cac5be701eb46cc7f24

Vendor Advisories for CVE-2026-73551(6)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17883293662026-09-08redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17883278662026-09-08redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17883339242026-09-08redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17882963282026-09-08redhat
redhatopenshift-service-mesh/istio-proxyv2-rhel9:17882947152026-09-08redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 11× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-23 18:26 UTCEG score recompute
  2. 2026-09-23 18:26 UTCVendor advisory
  3. 2026-09-23 17:54 UTCEPSS rescore
  4. 2026-09-23 17:27 UTCVendor advisory
  5. 2026-09-22 19:21 UTCEG score recompute
  6. 2026-09-22 19:21 UTCVendor advisory
  7. 2026-09-21 21:22 UTCEG score recompute
  8. 2026-09-21 21:22 UTCVendor advisory
  9. 2026-09-21 20:25 UTCEG score recompute
  10. 2026-09-21 20:25 UTCVendor advisory
  11. 2026-09-21 20:23 UTCMITRE cvelistV5first tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-73551?
CVE-2026-73551 is a medium vulnerability published on September 21, 2026. Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to 1.36.10, 1.37.6, 1.38.4, and 1.39.1, Envoy's URL normalization does not recognize dot and dotdot path segments when they carry semicolon parameters. A request such as /user/..;foo=bar/admin is therefore…
When was CVE-2026-73551 disclosed?
CVE-2026-73551 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-73551 actively exploited?
CVE-2026-73551 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 54.9% of all scored CVEs.
What is the CVSS score of CVE-2026-73551?
CVE-2026-73551 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-73551?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-73551, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-73551

Explore →

Is Your Infrastructure Affected by CVE-2026-73551?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Book a Demo →Browse All CVEs