Medium

jackson-databind: InetSocketAddress deserialization triggers eager DNS resolution (SSRF)

  • Disclosed: 23.06.2026
  • Updated: 11.10.2026 13:20

Summary

JDKFromStringDeserializer constructed InetSocketAddress with new InetSocketAddress(host, port), which performs eager DNS name resolution for hostname inputs at deserialization time. An application that binds untrusted JSON into a type containing an InetSocketAddress field issues an attacker-chosen DNS query during readValue, before any application-level validation or connect logic. The fix uses InetSocketAddress.createUnresolved(host, port), deferring DNS to an explicit connect.

Impact

An attacker controlling JSON deserialized into an InetSocketAddress-bearing type can force outbound DNS lookups for attacker-chosen hostnames at deserialization time (SSRF / DNS-based out-of-band interaction / internal-resolver probing), purely from binding.

Affected / Patched (verified via git tag --contains on 1f5a103)

  • 2.18 line: >= 2.18.0, < 2.18.8 -> fixed in 2.18.8
  • 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4
  • 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4

Severity / CWE

Maintainer: minor. Reporter: LOW. CWE-918 (SSRF).

Upstream fix

FasterXML/jackson-databind#5951 ("Improve InetSocketAddress deserialization"). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4.

Credits

Omkhar Arasaratnam (@omkhar) - finder.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) com.fasterxml.jackson.core:jackson-databind >= 2.0.0, < 2.18.8, >= 2.19.0, < 2.21.4, >= 3.0.0, < 3.1.4 2.18.8, 2.21.4, 3.1.4
Java / Kotlin (Maven) tools.jackson.core:jackson-databind >= 2.19.0, < 2.21.4, >= 3.0.0, < 3.1.4 2.21.4, 3.1.4

References

CVSS score 5.3/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Weakness (CWE)
CWE-918
Platform
Java / Kotlin (Maven)
Package
com.fasterxml.jackson.core:jackson-databind, tools.jackson.core:jackson-databind
Disclosed
23.06.2026
Updated
11.10.2026 13:20

Sources and licenses

OSV / GitHub Advisory Database - GHSA-hgj6-7826-r7m5 - CC BY 4.0

Vulnerability history: tools.jackson.core:jackson-databind

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

All (15) in the archive
Total entries
15
First → latest
06.2026 09.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • High 5
  • Medium 10

Disclosures per year

  1. 2026: 15
Severity:
  1. High · 7.5 CVE-2026-91777 >= 3.0.0, < 3.1.7, >= 3.2.0, < 3.2.3 3.1.7, 3.2.3
  2. High · 7.5 CVE-2026-91776 >= 3.0.0, < 3.1.7, >= 3.2.0, < 3.2.3 3.1.7, 3.2.3
  3. High · 7.5 CVE-2026-68497 >= 3.2.0, < 3.2.2, >= 3.0.0, < 3.1.6 3.2.2, 3.1.6
  4. jackson-databind: InetSocketAddress deserialization triggers eager DNS resolution (SSRF) this entry
    Medium · 5.3 CVE-2026-54514 >= 2.19.0, < 2.21.4, >= 3.0.0, < 3.1.4 2.21.4, 3.1.4

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