CVE-2026-91777Network attack vectorHinoki check available

Denial of service via quadratic forward-reference resolution

Published Sep 23, 2026 · Updated Sep 23, 2026

Uncontrolled resource consumption in FasterXML jackson-databind allows remote attackers to interrupt service via crafted JSON. CollectionDeserializer.CollectionReferringAccumulator.resolveForwardReference() and its MapDeserializer counterpart repeatedly scan pending object IDs and copy buffered entries, making reverse-order resolution quadratic. Exploitation requires an application to deserialize attacker-influenced JSON into an identity-enabled collection or map; exhaustion can consume request time or worker capacity.

CVSS severity7.5
High
EPSS probability0.45%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Uncontrolled resource consumption in FasterXML jackson-databind allows remote attackers to interrupt service via crafted JSON. CollectionDeserializer.CollectionReferringAccumulator.resolveForwardReference() and its MapDeserializer counterpart repeatedly scan pending object IDs and copy buffered entries, making reverse-order resolution quadratic. Exploitation requires an application to deserialize attacker-influenced JSON into an identity-enabled collection or map; exhaustion can consume request time or worker capacity.

The record

CVE
CVE-2026-91777
Published
Sep 23, 2026
Updated
Sep 23, 2026
Vendor
FasterXML
Product
jackson-databind
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.19.0 <=2.21.6
  2. Affected versionversion=2.22.0 <=2.22.2
  3. Affected versionversion=2.5.0 <=2.18.10
  4. Affected versionversion=3.0.0 <=3.1.6
  5. Affected versionversion=3.2.0 <=3.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FasterXML · jackson-databindversion=2.19.0 <=2.21.6; version=2.22.0 <=2.22.2; version=2.5.0 <=2.18.10; version=3.0.0 <=3.1.6; version=3.2.0 <=3.2.2

Published CVSS scores

7.5GitHubCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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