ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-91777

jackson-databind quadratic forward-reference completion

Published Sep 22, 2026 · catalog updated Sep 23, 2026 · BSI

Last checked Nov 3, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-91777. EPSS is 0.49%. Act only if a listed version of BSI is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
High7.5
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.49%
Remediation
Version ranges on file
Affected products
maven com.fasterxml.jackson.core:jackson-databind · maven tools.jackson.core:jackson-databind

### Summary When an collection or map first creates N unresolved object-ID references and later resolves the same IDs in reverse order, jackson-databind scans the remaining pending-reference accumulator for each resolution. A shallow JSON document whose size grows linearly can therefore cause quadratic CPU work during deserialization. ### Details The affected path is forward-reference completion in and the corresponding map implementation. The implementation performs a linear search of the pending accumulator for every resolved object ID. The behavior is runtime-confirmed in jackson-databind 2.5.0, 2.22.1, and 3.2.1. Current 2.22 and 3.2 source branches retained the same design when rechecked. A 2.4.0 control fails closed before successful reverse-order completion, so 2.5.0 is the conservative runtime-confirmed affected floor. The patched versions are: 2.18.11, 2.21.7, 2.22.3, 3.1.7 and 3.2.3. The vulnerable application must deserialize attacker-influenced JSON into an identity-enabled collection or map. The issue does not require deep nesting or syntactically unusual JSON. Suggested correction: replace repeated linear lookup/removal with a keyed pending-reference structure or another design that provides linear or amortized-linear completion. A regression should preserve input order, duplicate-ID behavior, and unresolved-ID errors while bounding reverse-order resolution work. ### PoC The proof constructs a shallow collection containing N unresolved references followed by definitions of those same IDs in reverse order. Its ID class counts calls, giving a deterministic work measure rather than a timing-dependent result. With N=2,000, affected versions perform exactly 2,003,000 ID comparisons. An equally sized control in which every reference is already resolved performs zero comparisons in the pending-reference lookup path. The run is bounded to a 512 MiB JVM. The result demonstrates quadratic growth: approximately comparisons, plus fixed setup comparisons. No attach

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • maven com.fasterxml.jackson.core:jackson-databind>= 2.19.0, <= 2.21.6
  • maven com.fasterxml.jackson.core:jackson-databind>= 2.22.0, <= 2.22.2
  • maven com.fasterxml.jackson.core:jackson-databind>= 2.5.0, <= 2.18.10
  • maven tools.jackson.core:jackson-databind>= 3.0.0, <= 3.1.6
  • maven tools.jackson.core:jackson-databind>= 3.2.0, <= 3.2.2

How to fix CVE-2026-91777

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-91777. EPSS is 0.49%. Act only if a listed version of BSI is installed.

Which versions are affected?

Compare what you have installed with >= 2.19.0, <= 2.21.6, >= 2.22.0, <= 2.22.2, >= 2.5.0, <= 2.18.10, >= 3.0.0, <= 3.1.6, >= 3.2.0, <= 3.2.2. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption. EPSS 0.49%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Jackson security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 23, 2026 · Maintainer security tabs

    Updated

    ### Summary When an collection or map first creates N unresolved object-ID references and later resolves the same IDs in reverse order, jackson-databind scans the remaining pending-reference accumulator for each resolution. A shallow JSON document whose size grows linearly can therefore cause quadratic CPU work during deserialization. ### Details The affected path is forward-reference completion i

  2. Oct 30, 2026 · BSI CERT-Bund

    Detected

    CVE-2026-91777 is listed by SOS GmbH JobScheduler: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff.

Sources

  • BSI CERT-BundGovernment advisoryCVE-2026-91777

    SOS GmbH JobScheduler: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

    wid.cert-bund.de
  • CVE.orgVulnerability recordCVE-2026-91777

    Official CVE identifier

    cve.org
  • Maintainer security tabsVendor advisoryGHSA-cxp5-3px4-pw24

    ### Summary When an collection or map first creates N unresolved object-ID references and later resolves the same IDs in reverse order, jackson-databind scans the remaining pending-reference accumulator for each resolution. A shallow JSON document whose size grows linearly can therefore cause quadratic CPU work during deserialization. ### Details The affected path is forward-reference completion i

    github.com

Freshness

Last verified in this catalog Nov 3, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • Maintainer security tabsNov 2, 2026
  • CVE.orgOct 31, 2026
  • BSI CERT-BundOct 31, 2026