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
Elevated
8.2EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.4%CVSS: 8.2Exploit: Elevated riskExposed services: Not assessed

A fixed version is listed under Patch Availability — apply it.

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
8.2HIGHmedium confidence
EG Risk
68
EG Risk 68/100

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%
EPSS PROB
0.4%
EPSS %ILE
27th
KEV
Not listed

Published

May 12, 2026

Last Modified

May 13, 2026

Advisory Details (1)

Auto-updated May 12, 2026
🔬 Proof of concept available. Fixed version listed under Patch Availability. Sources: github.
githubMentions a patch (unverified)🟡 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 / EcosystemFix (by version range) / 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 rangeFix by version rangeDependents
ssrfcheck—
  • every version through 1.3.0: no fix on record
—

Weakness Classification(2)

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

Data Freshness Timeline

(refreshed 7× 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.

Showing the most recent 100 of 220 total refreshes for this CVE.

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

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npm:ssrfcheck

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 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 0.4% probability of exploitation in the next 30 days (27th percentile of EPSS-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?
A fixed version for CVE-2026-43929 is listed under Patch Availability on this page: update to the version listed for your package.

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