CVE-2026-29057

MEDIUMNVD 6.56.5—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.5 under NVD CVSS v3. EPSS exploit probability: 0.4%, top 64% 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, nvd
6.5EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.5Exploit: None knownExposed: 0

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

Next.js is a React framework for building full-stack web applications. Starting in version 9.5.0 and prior to versions 15.5.13 and 16.1.7, when Next.js rewrites proxy traffic to an external backend, a crafted DELETE/OPTIONS request using Transfer-Encoding: chunked could trigger request boundary disagreement between the proxy and backend. This could allow request smuggling through rewritten routes. An attacker could smuggle a second request to unintended backend routes (for example, internal/admin endpoints), bypassing assumptions that only the configured rewrite destination/path is reachable. This does not impact applications hosted on providers that handle rewrites at the CDN level, such as Vercel. The vulnerability originated in an upstream library vendored by Next.js. It is fixed in Next.js 15.5.13 and 16.1.7 by updating that dependency’s behavior so content-length: 0 is added only when both content-length and transfer-encoding are absent, and transfer-encoding is no longer removed in that code path. If upgrading is not immediately possible, block chunked DELETE/OPTIONS requests on rewritten routes at the edge/proxy, and/or enforce authentication/authorization on backend routes.

CVSS v3
6.5
EG Score
6.5(medium)
EG Risk
34(Track)
EG Risk 34/100SSVC: 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
Severity65% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
37%
KEV
Not listed

Published

March 18, 2026

Last Modified

June 17, 2026

Advisory Details (4)

Auto-updated Aug 4, 2026
Patch available. Sources: github_commit, github_release, github.
github Patch Available

HTTP request smuggling in rewrites · Advisory · vercel/next.js · GitHub

https://github.com/vercel/next.js/security/advisories/GHSA-ggv3-7p47-pfv8
github_release Patch Available

v16.1.7

Patch available: vercel/next.js v16.1.7

https://github.com/vercel/next.js/releases/tag/v16.1.7
github_release Patch Available

v15.5.13

Patch available: vercel/next.js v15.5.13

https://github.com/vercel/next.js/releases/tag/v15.5.13
github_commit

commit dc98c04f376c (vercel/next.js)

Fix landed in vercel/next.js commit dc98c04f376c — awaiting tagged release

https://github.com/vercel/next.js/commit/dc98c04f376c6a1df76ec3e0a2d07edf4abdabd6

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
next—15.5.13—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 30× 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. 2026-09-18 19:28 UTCEPSS rescore
  2. 2026-09-18 19:27 UTCEPSS rescore
  3. 2026-09-17 19:30 UTCEPSS rescore
  4. 2026-09-16 14:08 UTCEPSS rescore
  5. 2026-09-16 05:15 UTCEPSS rescore
  6. 2026-09-13 16:47 UTCEPSS rescore
  7. 2026-09-12 15:01 UTCEPSS rescore
  8. 2026-09-11 14:52 UTCEPSS rescore
  9. 2026-09-10 09:34 UTCEPSS rescore
  10. 2026-09-08 22:00 UTCEPSS rescore
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-06 13:47 UTCEPSS rescore
  13. 2026-09-06 13:47 UTCEPSS rescore
  14. 2026-09-04 05:06 UTCEPSS rescore
  15. 2026-09-02 18:08 UTCOSV refresh
  16. 2026-09-02 14:11 UTCEPSS rescore
  17. 2026-09-01 13:53 UTCEPSS rescore
  18. 2026-09-01 04:39 UTCEPSS rescore
  19. 2026-09-01 04:39 UTCEPSS rescore
  20. 2026-08-30 19:17 UTCEPSS rescore
  21. 2026-08-30 01:22 UTCEPSS rescore
  22. 2026-08-28 21:41 UTCEPSS rescore
  23. 2026-08-27 14:25 UTCEPSS rescore
  24. 2026-08-26 14:46 UTCEPSS rescore
  25. 2026-08-25 13:49 UTCEPSS rescore
Show 37 more
  1. 2026-08-24 14:17 UTCEPSS rescore
  2. 2026-08-23 00:19 UTCEPSS rescore
  3. 2026-08-21 23:49 UTCEPSS rescore
  4. 2026-08-20 22:55 UTCEPSS rescore
  5. 2026-08-20 22:55 UTCEPSS rescore
  6. 2026-08-19 17:03 UTCEPSS rescore
  7. 2026-08-18 13:48 UTCEPSS rescore
  8. 2026-08-17 13:47 UTCEPSS rescore
  9. 2026-08-16 14:56 UTCEPSS rescore
  10. 2026-08-16 11:19 UTCEG score recompute
  11. 2026-08-16 02:14 UTCEPSS rescore
  12. 2026-08-15 01:30 UTCEPSS rescore
  13. 2026-08-14 07:26 UTCEG score recompute
  14. 2026-08-13 22:00 UTCEPSS rescore
  15. 2026-08-12 22:13 UTCEG score recompute
  16. 2026-08-12 13:50 UTCEPSS rescore
  17. 2026-08-11 13:42 UTCEPSS rescore
  18. 2026-08-11 06:36 UTCEG score recompute
  19. 2026-08-11 00:00 UTCEPSS rescore
  20. 2026-08-10 06:49 UTCEG score recompute
  21. 2026-08-09 13:46 UTCEPSS rescore
  22. 2026-08-09 07:01 UTCEG score recompute
  23. 2026-08-08 16:37 UTCEPSS rescore
  24. 2026-08-07 17:35 UTCEG score recompute
  25. 2026-08-06 13:46 UTCEPSS rescore
  26. 2026-08-06 01:41 UTCEG score recompute
  27. 2026-08-05 19:17 UTCEPSS rescore
  28. 2026-08-04 15:10 UTCEPSS rescore
  29. 2026-08-04 00:50 UTCEG score recompute
  30. 2026-08-03 10:36 UTCEPSS rescore
  31. 2026-08-02 16:44 UTCEG score recompute
  32. 2026-08-02 02:26 UTCEPSS rescore
  33. 2026-08-01 04:16 UTCEPSS rescore
  34. 2026-07-30 16:27 UTCEPSS rescore
  35. 2026-07-30 01:30 UTCEPSS rescore
  36. 2026-07-28 15:36 UTCEPSS rescore
  37. 2026-07-27 14:14 UTCEG score recompute

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-29057?
CVE-2026-29057 is a medium vulnerability published on March 18, 2026. Next.js is a React framework for building full-stack web applications. Starting in version 9.5.0 and prior to versions 15.5.13 and 16.1.7, when Next.js rewrites proxy traffic to an external backend, a crafted DELETE/OPTIONS request using Transfer-Encoding: chunked could trigger request boundary…
When was CVE-2026-29057 disclosed?
CVE-2026-29057 was first published in the National Vulnerability Database on March 18, 2026, with the most recent update on June 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-29057 actively exploited?
CVE-2026-29057 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 63.4% of all scored CVEs.
What is the CVSS score of CVE-2026-29057?
CVE-2026-29057 has a CVSS v3 base score of 6.5 (NVD).
How do I remediate CVE-2026-29057?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-29057, 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-2026-29057

Explore →

Is Your Infrastructure Affected by CVE-2026-29057?

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

Start Free Scan →Browse All CVEs