NVD / CVE Program· CNA HeroDevs

CVE-2026-91777: jackson-databind: quadratic forward-reference completion in Collection and Map deserializers

Noroxi assessment

Priority: Monitor (action score 30/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 0.48% (FIRST EPSS).
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: apache-commons-collections (AlmaLinux:8) 3.2.2-10.module_el8.5.0+2577+9e95fe00; apache-commons-lang (AlmaLinux:8) 2.6-21.module_el8.5.0+2577+9e95fe00; apache-commons-net (AlmaLinux:8) 3.6-3.module_el8.5.0+2577+9e95fe00.

Low priority for now. Upgrade to apache-commons-collections (AlmaLinux:8) 3.2.2-10.module_el8.5.0+2577+9e95fe00; apache-commons-lang (AlmaLinux:8) 2.6-21.module_el8.5.0+2577+9e95fe00; apache-commons-net (AlmaLinux:8) 3.6-3.module_el8.5.0+2577+9e95fe00 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

HighCVSS 7.5 · v3.1—No exploit Fix available

Published: Sep 22, 2026
Updated: Sep 24, 2026
EPSS: 0.4% · 42th percentile
CWE: CWE-400

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 30 / 40 · 7.5 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 0.4%

CISA SSVC decision

Exploitation: proof of concept
Automatable: yes
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · HeroDevs: 7.5; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (HeroDevs). Independent of NVD's CPE analysis and usually ahead of it.

FasterXML jackson-databind
- 2.5.0 and later · up to and including 2.18.10affected · maven
- 2.19.0 and later · up to and including 2.21.6affected · maven
- 2.22.0 and later · up to and including 2.22.2affected · maven
- 3.0.0 and later · up to and including 3.1.6affected · maven
- 3.2.0 and later · up to and including 3.2.2affected · maven

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

+89

Same product

fasterxml: all records

Other highest-scoring records for the same primary product.

CVE-2017-17485FasterXML jackson-databind through 2.8.10 and 2.9.x through 2.9.3 allows unauthenticated remote code execution because of an incomplete fix
54Plan
CVE-2017-7525A deserialization flaw was discovered in the jackson-databind, versions before 2.6.7.1, 2.7.9.1 and 2.8.9, which could allow an unauthentica
50Plan
CVE-2020-8840FasterXML jackson-databind 2.0.0 through 2.9.10.2 lacks certain xbean-reflect/JNDI blocking, as demonstrated by org.apache.xbean.propertyedi
47Plan

Published before and after this one in the same product

← EarlierCVE-2026-68497Sep 11, 2026 · jackson-databind: unbounded numeric parse in Duration and XMLGregorianCalendar deserialization allows CPU denial of service
30Monitor
← EarlierCVE-2026-91776Sep 22, 2026 · jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID
30Monitor
Later →CVE-2026-110879Oct 28, 2026 · jackson-databind: PolymorphicTypeValidator bypass via generic type arguments and array element types allows arbitrary class instantiation (incomplete fix for CV
39Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
almalinux:apache-commons-collections	3.2.2-10.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:apache-commons-lang	2.6-21.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:apache-commons-net	3.6-3.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:bea-stax-api	1.2.0-16.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:glassfish-fastinfoset	1.2.13-9.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:glassfish-jaxb-api	2.2.12-8.module_el8.5.0+2577+9e95fe00 · AlmaLinux:8	Package registry (OSV)
almalinux:glassfish-jaxb-core	2.2.11-12.module_el8.10.0+3791+e0637953 · AlmaLinux:8	Package registry (OSV)
almalinux:glassfish-jaxb-runtime	2.2.11-12.module_el8.10.0+3791+e0637953 · AlmaLinux:8	Package registry (OSV)
almalinux:glassfish-jaxb-txw2	2.2.11-12.module_el8.10.0+3791+e0637953 · AlmaLinux:8	Package registry (OSV)
almalinux:jackson-annotations	2.21-1.module_el8.10.0+4235+0924958e · AlmaLinux:8	Package registry (OSV)
almalinux:jackson-core	2.21.4-1.module_el8.10.0+4329+908ad137.3 · AlmaLinux:8	Package registry (OSV)
almalinux:pki-jackson-databind	2.21.6-1.el9_8.1 · AlmaLinux:9	Package registry (OSV)
debian:jackson-databind	2.18.11-1 · Debian:14	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	2.18.11	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	2.21.7	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	2.22.3	Package registry (OSV)
Maven:tools.jackson.core:jackson-databind	3.1.7	Package registry (OSV)
Maven:tools.jackson.core:jackson-databind	3.2.3	Package registry (OSV)
opensuse:jackson-annotations	2.18.11-160000.1.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:jackson-core	2.18.11-160000.1.1 · openSUSE:Leap 16.0	Package registry (OSV)
opensuse:jackson-databind	2.18.11-1.1 · openSUSE:Tumbleweed	Package registry (OSV)
red hat:jackson-databind	0:2.21.6-1.el9_8.1 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
red hat:pki-jackson-databind	0:2.21.6-1.el9_8.1 · Red Hat:enterprise_linux:9::appstream	Package registry (OSV)
rocky linux:apache-commons-collections	0:3.2.2-10.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:apache-commons-lang	0:2.6-21.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:apache-commons-net	0:3.6-3.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:bea-stax	0:1.2.0-16.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:glassfish-fastinfoset	0:1.2.13-9.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:glassfish-jaxb	0:2.2.11-12.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)
rocky linux:glassfish-jaxb-api	0:2.2.12-8.module+el8.10.0+1763+c7c02164 · Rocky Linux:8	Package registry (OSV)

+13

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Daniel Birtwhistle (dabirt)finder

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-917760 days apartjackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID
30Monitor
CVE-2026-6849711 days apartjackson-databind: unbounded numeric parse in Duration and XMLGregorianCalendar deserialization allows CPU denial of service
30Monitor
CVE-2026-5019391 days apartjackson-databind: Deeply nested JsonNode throws StackOverflowError for toString()
25Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: none
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: None
Availability impact: High

Weakness class (CWE)

CWE-400 · Uncontrolled Resource Consumption

CVSS vector

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

nvd-secondary

Root cause

Code that parses nested structures sets no depth or size limit. A small input can turn into a disproportionate processing load.

The bug in code

The whole CWE-400 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1function expand(node) {
2  return node.children.map(expand);
3}

Fixed

1const MAX_DEPTH = 32;
2function expand(node, depth = 0) {
3  if (depth > MAX_DEPTH) throw new Error("too deep");
4  return node.children.map((c) => expand(c, depth + 1));
5}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

Endpoint Denial of ServiceT1499

Change log

Fix✗ → ✓Sep 28, 2026, 10:48 PM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/FasterXML/jackson-databind/issues/6204

Show all references (1 more)

github.com/FasterXML/jackson-databind/security/advisories/GHSA-cxp5-3px4-pw24

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records

Ecosystem	Package	Affected range	Fix
AlmaLinux:8	apache-commons-collections	before 3.2.2-10.module_el8.5.0+2577+9e95fe00	3.2.2-10.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	apache-commons-lang	before 2.6-21.module_el8.5.0+2577+9e95fe00	2.6-21.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	apache-commons-net	before 3.6-3.module_el8.5.0+2577+9e95fe00	3.6-3.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	bea-stax-api	before 1.2.0-16.module_el8.5.0+2577+9e95fe00	1.2.0-16.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	glassfish-fastinfoset	before 1.2.13-9.module_el8.5.0+2577+9e95fe00	1.2.13-9.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	glassfish-jaxb-api	before 2.2.12-8.module_el8.5.0+2577+9e95fe00	2.2.12-8.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	glassfish-jaxb-core	before 2.2.11-12.module_el8.10.0+3791+e0637953	2.2.11-12.module_el8.10.0+3791+e0637953
AlmaLinux:8	glassfish-jaxb-runtime	before 2.2.11-12.module_el8.10.0+3791+e0637953	2.2.11-12.module_el8.10.0+3791+e0637953
AlmaLinux:8	glassfish-jaxb-txw2	before 2.2.11-12.module_el8.10.0+3791+e0637953	2.2.11-12.module_el8.10.0+3791+e0637953
AlmaLinux:8	jackson-annotations	before 2.21-1.module_el8.10.0+4235+0924958e	2.21-1.module_el8.10.0+4235+0924958e
AlmaLinux:8	jackson-core	before 2.21.4-1.module_el8.10.0+4329+908ad137.3	2.21.4-1.module_el8.10.0+4329+908ad137.3
AlmaLinux:8	jackson-databind	before 2.21.4-1.module_el8.10.0+4329+908ad137.1	2.21.4-1.module_el8.10.0+4329+908ad137.1
AlmaLinux:8	jackson-jaxrs-json-provider	before 2.21.4-1.module_el8.10.0+4235+0924958e	2.21.4-1.module_el8.10.0+4235+0924958e
AlmaLinux:8	jackson-jaxrs-providers	before 2.21.4-1.module_el8.10.0+4235+0924958e	2.21.4-1.module_el8.10.0+4235+0924958e
AlmaLinux:8	jackson-module-jaxb-annotations	before 2.21.4-2.module_el8.10.0+4235+0924958e	2.21.4-2.module_el8.10.0+4235+0924958e
AlmaLinux:8	jakarta-commons-httpclient	before 1:3.1-28.module_el8.5.0+2577+9e95fe00	1:3.1-28.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	javassist	before 3.18.1-8.module_el8.5.0+2577+9e95fe00	3.18.1-8.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	javassist-javadoc	before 3.18.1-8.module_el8.5.0+2577+9e95fe00	3.18.1-8.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	pki-servlet-engine	before 1:9.0.62-1.module_el8.10.0+3791+e0637953	1:9.0.62-1.module_el8.10.0+3791+e0637953
AlmaLinux:8	relaxngDatatype	before 2011.1-7.module_el8.5.0+2577+9e95fe00	2011.1-7.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	slf4j	before 1.7.25-4.module_el8.5.0+2577+9e95fe00	1.7.25-4.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	slf4j-jdk14	before 1.7.25-4.module_el8.5.0+2577+9e95fe00	1.7.25-4.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	stax-ex	before 1.7.7-8.module_el8.5.0+2577+9e95fe00	1.7.7-8.module_el8.5.0+2577+9e95fe00
AlmaLinux:8	velocity	before 1.7-24.module_el8.5.0+2577+9e95fe00	1.7-24.module_el8.5.0+2577+9e95fe00