CVE-2026-71849

LOWPre-NVD 3.73.7
EchelonGraph scoreMEDIUM confidence

This low-severity CVE scores 3.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 85% 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
3.7EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 3.7Exploit: None knownExposed: 0

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

Hono is a Web application framework that provides support for any JavaScript runtime. From 4.7.0 to 4.12.33, the Proxy Helper proxy() function in hono/proxy does not remove response headers named by the origin's Connection header. Per RFC 9110 Section 7.6.1, an intermediary must remove the header fields listed in a message's Connection header field before forwarding the message, in addition to the well known hop by hop headers, but the proxy() function only removed the well known hop by hop headers, including Connection itself, from origin responses. A client may therefore receive response headers that the origin intended only for its immediate peer, disclosing connection scoped or internal metadata contained in such headers, when an application proxies responses from an origin that declares additional, non standard headers as hop by hop via the Connection response header. This issue is fixed in version 4.12.34.

CVSS v3
3.7
EG Score
3.7(medium)
EG Risk
17(Track)
EG Risk 17/100SSVC: 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
Severity37% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
15%
KEV
Not listed

Published

August 7, 2026

Last Modified

August 10, 2026

Vendor Advisories for CVE-2026-71849(1)

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

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
hono4.12.34

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 11× in last 7d / 22× 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. 2026-08-20 22:56 UTCEPSS rescore
  2. 2026-08-19 17:04 UTCEPSS rescore
  3. 2026-08-19 04:32 UTCEG score recompute
  4. 2026-08-18 13:49 UTCEPSS rescore
  5. 2026-08-18 13:49 UTCEPSS rescore
  6. 2026-08-17 13:47 UTCEPSS rescore
  7. 2026-08-16 14:56 UTCEPSS rescore
  8. 2026-08-16 14:56 UTCEPSS rescore
  9. 2026-08-16 07:29 UTCEG score recompute
  10. 2026-08-16 02:15 UTCEPSS rescore
  11. 2026-08-15 01:31 UTCEPSS rescore
  12. 2026-08-13 22:00 UTCEPSS rescore
  13. 2026-08-13 10:29 UTCEG score recompute
  14. 2026-08-12 13:51 UTCEPSS rescore
  15. 2026-08-11 00:00 UTCEPSS rescore
  16. 2026-08-10 13:29 UTCEG score recompute
  17. 2026-08-10 12:24 UTCEG score recompute
  18. 2026-08-09 13:47 UTCEPSS rescore
  19. 2026-08-08 16:37 UTCEPSS rescore
  20. 2026-08-07 19:28 UTCEG score recompute
  21. 2026-08-07 18:47 UTCEG score recompute
  22. 2026-08-07 18:47 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-71849?
CVE-2026-71849 is a low vulnerability published on August 7, 2026. Hono is a Web application framework that provides support for any JavaScript runtime. From 4.7.0 to 4.12.33, the Proxy Helper proxy() function in hono/proxy does not remove response headers named by the origin's Connection header. Per RFC 9110 Section 7.6.1, an intermediary must remove the header…
When was CVE-2026-71849 disclosed?
CVE-2026-71849 was first published in the National Vulnerability Database on August 7, 2026, with the most recent update on August 10, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-71849 actively exploited?
CVE-2026-71849 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 85.2% of all scored CVEs.
What is the CVSS score of CVE-2026-71849?
CVE-2026-71849 has a CVSS v3 base score of 3.7 (NVD).
How do I remediate CVE-2026-71849?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71849, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-71849

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