CVE-2026-43929

HIGHNVD 8.28.2—
EchelonGraph scoreMEDIUM confidence

Score 8.2 from GitHub Security Advisory (severity: HIGH) published 2026-05-05. NVD baseline CVSS 8.2; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Trending — 3 sources updated this weekElevated
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 8.2Exploit: Elevated riskExposed: 0

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

ssrfcheck is a library that checks if a string contains a potential SSRF attack. In 1.3.0 and earlier, ssrfcheck fails to block Server-Side Request Forgery attacks when the target private IP address is encoded as an IPv4-mapped IPv6 address (e.g. http://[::ffff:127.0.0.1]/). The WHATWG URL parser built into Node.js silently normalizes the IPv4 notation inside the brackets to compressed hex form ([::ffff:7f00:1]) before the library's private-IP regex ever runs. The regex was written to match dot-notation only and therefore never matches any real input — all seven IANA private IPv4 ranges, including the AWS/GCP/Azure metadata address 169.254.169.254, are bypassed. Any application using isSSRFSafeURL() to guard HTTP requests made with user-supplied URLs is fully exposed to SSRF.

CVSS v3
8.2
EG Score
8.2(medium)
EG Risk
68(Attend)
EG Risk 68/100SSVC: Attend

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
Severity82% × 45%
Exploitation40% × 40%
Automatability100% × 15%
Action: Remediate soon — notable exploitation risk.
EPSS PROB
0%
EPSS %ILE
13%
KEV
Not listed

Published

May 12, 2026

Last Modified

May 13, 2026

Advisory Details (1)

Auto-updated May 12, 2026
🔬 Proof of concept available. Patch available. Sources: github.
github Patch Available🟡 PoC Available

Server-Side Request Forgery (SSRF) and Incomplete List of Disallowed Inputs in ssrfcheck · Advisory · felippe-regazio/ssrfcheck · GitHub

https://github.com/felippe-regazio/ssrfcheck/security/advisories/GHSA-j4rj-2jr5-m439

Patch Availability(1)

Vendor / EcosystemFixed in / PatchReleasedSource
npmssrfcheck—ghsa

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.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
ssrfcheck———

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 6× in last 7d / 65× 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.

Showing the most recent 100 of 188 total refreshes for this CVE.

  1. 2026-08-26 14:46 UTCEPSS rescore
  2. 2026-08-25 13:49 UTCEPSS rescore
  3. 2026-08-23 18:11 UTCEG score recompute
  4. 2026-08-23 18:11 UTCGHSA enrichment
  5. 2026-08-21 23:49 UTCEPSS rescore
  6. 2026-08-20 22:55 UTCEPSS rescore
  7. 2026-08-19 17:04 UTCEPSS rescore
  8. 2026-08-18 13:48 UTCEPSS rescore
  9. 2026-08-17 13:47 UTCEPSS rescore
  10. 2026-08-17 10:49 UTCEG score recompute
  11. 2026-08-17 10:49 UTCGHSA enrichment
  12. 2026-08-16 14:56 UTCEPSS rescore
  13. 2026-08-16 04:12 UTCEG score recompute
  14. 2026-08-16 04:12 UTCGHSA enrichment
  15. 2026-08-16 02:14 UTCEPSS rescore
  16. 2026-08-15 01:30 UTCEPSS rescore
  17. 2026-08-15 01:00 UTCGHSA enrichment
  18. 2026-08-14 13:51 UTCGHSA enrichment
  19. 2026-08-14 02:42 UTCEG score recompute
  20. 2026-08-14 02:42 UTCGHSA enrichment
  21. 2026-08-13 22:00 UTCEPSS rescore
  22. 2026-08-13 03:08 UTCGHSA enrichment
  23. 2026-08-12 15:59 UTCEG score recompute
  24. 2026-08-12 15:59 UTCGHSA enrichment
  25. 2026-08-12 13:51 UTCEPSS rescore
Show 75 more
  1. 2026-08-11 15:40 UTCEG score recompute
  2. 2026-08-11 15:40 UTCGHSA enrichment
  3. 2026-08-11 13:43 UTCEPSS rescore
  4. 2026-08-11 01:03 UTCEG score recompute
  5. 2026-08-11 01:03 UTCGHSA enrichment
  6. 2026-08-11 00:00 UTCEPSS rescore
  7. 2026-08-10 11:32 UTCGHSA enrichment
  8. 2026-08-10 00:20 UTCEG score recompute
  9. 2026-08-10 00:20 UTCGHSA enrichment
  10. 2026-08-09 13:46 UTCEPSS rescore
  11. 2026-08-09 13:12 UTCGHSA enrichment
  12. 2026-08-09 02:03 UTCEG score recompute
  13. 2026-08-09 02:03 UTCGHSA enrichment
  14. 2026-08-08 16:37 UTCEPSS rescore
  15. 2026-08-08 05:32 UTCGHSA enrichment
  16. 2026-08-07 18:23 UTCEG score recompute
  17. 2026-08-07 18:23 UTCGHSA enrichment
  18. 2026-08-07 07:14 UTCGHSA enrichment
  19. 2026-08-06 20:05 UTCEG score recompute
  20. 2026-08-06 20:05 UTCGHSA enrichment
  21. 2026-08-06 13:46 UTCEPSS rescore
  22. 2026-08-06 08:56 UTCGHSA enrichment
  23. 2026-08-05 21:47 UTCEG score recompute
  24. 2026-08-05 21:47 UTCGHSA enrichment
  25. 2026-08-05 19:17 UTCEPSS rescore
  26. 2026-08-04 15:10 UTCEPSS rescore
  27. 2026-08-04 10:38 UTCEPSS rescore
  28. 2026-08-03 19:14 UTCEG score recompute
  29. 2026-08-03 19:14 UTCGHSA enrichment
  30. 2026-08-03 10:36 UTCEPSS rescore
  31. 2026-08-02 21:08 UTCGHSA enrichment
  32. 2026-08-02 09:59 UTCEG score recompute
  33. 2026-08-02 09:59 UTCGHSA enrichment
  34. 2026-08-02 02:27 UTCEPSS rescore
  35. 2026-08-01 22:50 UTCEG score recompute
  36. 2026-08-01 22:50 UTCGHSA enrichment
  37. 2026-08-01 04:16 UTCEPSS rescore
  38. 2026-07-30 16:28 UTCEPSS rescore
  39. 2026-07-30 01:30 UTCEPSS rescore
  40. 2026-07-28 15:36 UTCEPSS rescore
  41. 2026-07-27 14:13 UTCEPSS rescore
  42. 2026-07-26 14:54 UTCEPSS rescore
  43. 2026-07-26 14:54 UTCEPSS rescore
  44. 2026-07-25 14:18 UTCEPSS rescore
  45. 2026-07-24 14:17 UTCEPSS rescore
  46. 2026-07-23 14:18 UTCEPSS rescore
  47. 2026-07-23 03:14 UTCEG score recompute
  48. 2026-07-22 14:08 UTCEPSS rescore
  49. 2026-07-21 15:24 UTCEPSS rescore
  50. 2026-07-20 17:08 UTCEPSS rescore
  51. 2026-07-19 14:31 UTCEPSS rescore
  52. 2026-07-19 02:29 UTCEPSS rescore
  53. 2026-07-18 10:04 UTCEPSS rescore
  54. 2026-07-16 17:03 UTCEPSS rescore
  55. 2026-07-15 16:57 UTCEPSS rescore
  56. 2026-07-15 02:00 UTCEPSS rescore
  57. 2026-07-13 22:30 UTCEPSS rescore
  58. 2026-07-13 06:13 UTCEPSS rescore
  59. 2026-07-12 05:46 UTCEPSS rescore
  60. 2026-07-11 08:27 UTCEPSS rescore
  61. 2026-07-09 19:10 UTCEPSS rescore
  62. 2026-07-08 15:16 UTCEPSS rescore
  63. 2026-07-07 13:46 UTCEPSS rescore
  64. 2026-07-06 16:27 UTCEPSS rescore
  65. 2026-07-06 02:23 UTCEPSS rescore
  66. 2026-07-05 02:30 UTCEPSS rescore
  67. 2026-07-04 06:31 UTCEPSS rescore
  68. 2026-07-01 15:07 UTCEPSS rescore
  69. 2026-06-30 23:22 UTCEPSS rescore
  70. 2026-06-29 14:06 UTCEPSS rescore
  71. 2026-06-28 14:07 UTCEPSS rescore
  72. 2026-06-28 12:59 UTCGHSA enrichment
  73. 2026-06-28 04:56 UTCEPSS rescore
  74. 2026-06-28 01:27 UTCGHSA enrichment
  75. 2026-06-27 08:20 UTCGHSA enrichment

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-43929?
CVE-2026-43929 is a high vulnerability published on May 12, 2026. ssrfcheck is a library that checks if a string contains a potential SSRF attack. In 1.3.0 and earlier, ssrfcheck fails to block Server-Side Request Forgery attacks when the target private IP address is encoded as an IPv4-mapped IPv6 address (e.g. http://[::ffff:127.0.0.1]/). The WHATWG URL parser…
When was CVE-2026-43929 disclosed?
CVE-2026-43929 was first published in the National Vulnerability Database on May 12, 2026, with the most recent update on May 13, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-43929 actively exploited?
CVE-2026-43929 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 86.8% of all scored CVEs.
What is the CVSS score of CVE-2026-43929?
CVE-2026-43929 has a CVSS v3 base score of 8.2 (NVD).
How do I remediate CVE-2026-43929?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-43929, 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-2026-43929

Explore →

Is Your Infrastructure Affected by CVE-2026-43929?

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

Start Free Scan →Browse All CVEs