CVE-2026-55233

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 73% 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 — 3 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

OpenResty is a high performance web platform. From 1.29.2.1 to before 1.29.2.5, an out-of-bounds write vulnerability exists in the upstream PROXY protocol v2 implementation. When OpenResty is configured to send PROXY protocol version 2 headers to upstream servers, constructing the header in the stream proxy protocol v2 patch can write beyond the bounds of the allocated buffer, causing the worker process to crash and resulting in a denial of service. Only configurations that explicitly enable PROXY protocol v2 for upstream connections are impacted. This issue is fixed in version 1.29.2.5.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
26.5%
KEV
Not listed

Published

July 10, 2026

Last Modified

July 14, 2026

Advisory Details (2)

Auto-updated Jul 10, 2026
Patch available. Sources: github_commit, github.
github Patch Available

Buffer overflow when writing PROXY protocol v2 header to upstream · Advisory · openresty/openresty · GitHub

https://github.com/openresty/openresty/security/advisories/GHSA-wx83-v28q-68gx
github_commit

commit 5c56ad2958a2 (openresty/openresty)

Fix landed in openresty/openresty commit 5c56ad2958a2 — awaiting tagged release

https://github.com/openresty/openresty/commit/5c56ad2958a2dad8b2cc99f4987b8642cbc647d1

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 20× in last 7d / 20× 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. 2026-07-15 18:53 UTCEG score recompute
  2. 2026-07-15 16:57 UTCEPSS rescore
  3. 2026-07-15 16:57 UTCEPSS rescore
  4. 2026-07-15 07:04 UTCEG score recompute
  5. 2026-07-15 02:00 UTCEPSS rescore
  6. 2026-07-15 02:00 UTCEPSS rescore
  7. 2026-07-14 19:15 UTCEG score recompute
  8. 2026-07-14 07:25 UTCEG score recompute
  9. 2026-07-13 22:31 UTCEPSS rescore
  10. 2026-07-13 19:36 UTCEG score recompute
  11. 2026-07-13 07:45 UTCEG score recompute
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-12 19:56 UTCEG score recompute
  15. 2026-07-12 08:07 UTCEG score recompute
  16. 2026-07-12 05:46 UTCEPSS rescore
  17. 2026-07-11 20:18 UTCEG score recompute
  18. 2026-07-11 08:28 UTCEG score recompute
  19. 2026-07-10 20:39 UTCEG score recompute
  20. 2026-07-10 20:37 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-55233?
CVE-2026-55233 is a high vulnerability published on July 10, 2026. OpenResty is a high performance web platform. From 1.29.2.1 to before 1.29.2.5, an out-of-bounds write vulnerability exists in the upstream PROXY protocol v2 implementation. When OpenResty is configured to send PROXY protocol version 2 headers to upstream servers, constructing the header in the…
When was CVE-2026-55233 disclosed?
CVE-2026-55233 was first published in the National Vulnerability Database on July 10, 2026, with the most recent update on July 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55233 actively exploited?
CVE-2026-55233 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 26.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55233?
CVE-2026-55233 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-55233?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55233, 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

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