Vulnerability-Lookup

(CVE-2026-91777)

Vulnerability from cleanstart – Published: 2026-09-25 00:37 – Updated: 2026-09-24 07:01 – Source website

Summary

Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID

Details

Security vulnerability affects the apache-nifi package. Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID.

Severity

9.8 (Critical)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

URL

Type

	https://github.com/cleanstart-dev/cleanstart-secu…	ADVISORY
	https://osv.dev/vulnerability/CVE-2026-91777	WEB
	https://nvd.nist.gov/vuln/detail/CVE-2026-91777	WEB

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "CleanStart",
        "name": "apache-nifi"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.10.0-r11"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [],
  "database_specific": {},
  "details": "Security vulnerability affects the apache-nifi package. Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID.",
  "id": "CLEANSTART-2026-DY58341",
  "modified": "2026-09-24T07:01:08Z",
  "published": "2026-09-25T00:37:04.308738Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/cleanstart-dev/cleanstart-security-advisories/tree/main/advisories/2026/CLEANSTART-2026-DY58341.json"
    },
    {
      "type": "WEB",
      "url": "https://osv.dev/vulnerability/CVE-2026-91777"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91777"
    }
  ],
  "related": [],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID",
  "upstream": [
    "CVE-2026-91777"
  ]
}

CVE-2026-91777 (GCVE-0-2026-91777)

Vulnerability from cvelistv5 – Published: 2026-09-23 02:21 – Updated: 2026-09-23 14:05

Title

jackson-databind: quadratic forward-reference completion in Collection and Map deserializers

Summary

Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID. The affected paths are CollectionDeserializer.CollectionReferringAccumulator.resolveForwardReference() and the equivalent implementation in MapDeserializer. When a document first creates N unresolved object-ID references in an identity-enabled collection or map and then defines those same IDs in reverse order, completion performs on the order of N * (N + 1) / 2 identity comparisons, so a shallow document whose size grows linearly causes quadratic CPU work during deserialization. The reporter instrumented equals() calls on the ID class and measured exactly 2,003,000 comparisons at N = 2,000, against zero comparisons in the pending-reference lookup path for an equally sized control in which every reference was already resolved. The input requires no deep nesting and no syntactically unusual JSON. Exploitation requires an application that deserializes attacker-influenced JSON into an identity-enabled collection or map. The fix replaces the repeated linear lookup with a keyed pending-reference structure.

Severity

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-23 14:04 UTC

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

HeroDevs mitre root

References

2 references

URL	Tags
https://github.com/FasterXML/jackson-databind/sec…	vendor-advisory
https://github.com/FasterXML/jackson-databind/iss…	patch

Impacted products

2 products

Vendor	Product	Version
FasterXML	jackson-databind	Affected: 2.5.0 , ≤ 2.18.10 (maven) Affected: 2.19.0 , ≤ 2.21.6 (maven) Affected: 2.22.0 , ≤ 2.22.2 (maven)
FasterXML	jackson-databind	Affected: 3.0.0 , ≤ 3.1.6 (maven) Affected: 3.2.0 , ≤ 3.2.2 (maven)

Credits

Daniel Birtwhistle (dabirt)

Show details on NVD website

JSON

To clipboard

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                "id": "CVE-2026-91777",
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                  },
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                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-23T14:04:51.226591Z",
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            }
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        }
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Action not permitted

(CVE-2026-91777)

CVE-2026-91777 (GCVE-0-2026-91777)

Tags

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Nomenclature

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