CVE-2026-91776

HIGHPre-NVD 7.57.5
EchelonGraph scoreMEDIUM confidence

“—” beside the score: it is equal to the CVSS score beside it.

Score 7.5 from GitHub Security Advisory (severity: HIGH) published 2026-09-30. A secondary CVSS source baseline 7.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: EPSS, GitHub Security Advisory, a secondary CVSS source
Trending — 4 sources updated this weekElevated

Also known asEUVD-2026-85002 (ENISA EUVD) · GHSA-wv8q-qhhj-9h54 (GitHub Security Advisories)Source: ENISA EUVD

7.5EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines at low or medium mission impact and sooner than that at high (the SSVC decision on this page).
  • CISA's Vulnrichment rates exploitation as PoC; EchelonGraph holds no exploit-code reference for it
CISA-KEV: Not listedEPSS PROB: 0.5%CVSS: 7.5Exploit: No code on recordExposed services: Not assessed

A fix is available — apply it.

TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID.

CVSS v3
7.5
EG Score
7.5HIGHmedium confidence
EG Risk
65
EG Risk 65/100

EG Risk is EchelonGraph's 0–100 priority score. It fuses impact severity (EG Severity, the CVSS base score, never the KEV-floored or EPSS-lifted EG Score) with real-world exploitation and automatability, under weights EchelonGraph set by hand, so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner.

How it’s computed (value × EchelonGraph’s weight)
Severity75% × 45%
Impact severity (EG Severity): CVSS 7.5 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation40% × 40%
EchelonGraph's fixed weight for EG-KEV Tier 3 (Elevated): a constant, not a probability.
Automatability100% × 15%
CISA's SSVC Automatable value: yes (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Attend at high (mission-essential systems).
Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
0.5%
EPSS %ILE
41st
KEV
Not listed

What the EG score is made of (scorer v4.0: the three questions the 0–10 score mixes, published apart · methodology)

The EG score (7.5): severity, escalated by confirmed exploitation. This CVE's 7.5 is its impact severity (EG Severity), not escalated.

EG Severity
7.5 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.GitHub Security Advisory CVSS
EG Likelihood
0.5% within 30 daysSource: FIRST EPSS (model v2026.06.15, score date 2026-10-31). FIRST's exploitation probability, not an EchelonGraph model.
Confirmed exploitation
None on record (CISA KEV, EG-KEV Tier 1)Reported apart from the likelihood: an observed fact, not a probability.
EG Priority
SSVC Track at medium mission impactTrack at low or medium mission impact; Attend at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; 60 days if it is not.Each input and its source, and whom BOD 26-04 binds: the SSVC and BOD 26-04 blocks below.

SSVC (CISA's decision table, applied by EchelonGraph)Track at low or medium mission impact; Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation public PoC (CISA Vulnrichment) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). All three are CISA's SSVC values (Vulnrichment). EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE. Mission impact is CISA's Mission & Well-being decision point, and only you can judge it. CISA's table makes it high when Mission Prevalence is Essential — the vulnerable component "directly provides capabilities that constitute at least one MEF for at least one entity" (MEF: mission essential function) — or when Public Well-Being Impact is Irreversible: "multiple fatalities are likely", the cyber-physical system "is likely lost or destroyed", "extreme or serious externalities" are imposed on other parties, or social systems such as elections or the financial grid "are destabilized and potentially collapse". CISA's decision table

BOD 26-04 (CISA's remediation timeline, Table 1)14 days if the affected system is publicly exposed; 60 days if it is not.

The score's inputs: In CISA KEV no (CISA's KEV catalog) · Automatable yes (CISA Vulnrichment) · Technical impact partial (CISA Vulnrichment). Whether your system is publicly exposed is yours to answer. BOD 26-04 binds US Federal Civilian Executive Branch agencies; for anyone else it is CISA's published timeline, a reference rather than an obligation. The directive · how EchelonGraph applies it

Published

September 23, 2026

Last Modified

September 24, 2026

Advisory Details (2)

Auto-updated Sep 23, 2026
Patch available. Sources: github.
Web page

Prevent unbounded growth of type id cache in `TypeDeserializer` [CVE-2026-91776] by pjfanning · Pull Request #6203 · FasterXML/jackson-databind · GitHub

https://github.com/FasterXML/jackson-databind/issues/6203
GitHub advisoryMentions a patch (unverified)

jackson-databind retains every unknown raw type ID · Advisory · FasterXML/jackson-databind · GitHub

https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54

Patch Availability(6)

Vendor / EcosystemFix (by version range) / PatchReleasedSource
redhatcom.fasterxml.jackson.core/jackson-databind:2.21.7.redhat-000012026-10-15redhat
mavencom.fasterxml.jackson.core:jackson-databind @ 2.18.11 (fixes >= 2.0.0, <= 2.18.10)—ghsa
mavencom.fasterxml.jackson.core:jackson-databind @ 2.21.7 (fixes >= 2.19.0, <= 2.21.6)—ghsa
mavencom.fasterxml.jackson.core:jackson-databind @ 2.22.3 (fixes >= 2.22.0, <= 2.22.2)—ghsa
maventools.jackson.core:jackson-databind @ 3.1.7 (fixes >= 3.0.0, <= 3.1.6)—ghsa
maventools.jackson.core:jackson-databind @ 3.2.3 (fixes >= 3.2.0, <= 3.2.2)—ghsa

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(5 across 4 ecosystems)
Maven(2)
PackageVulnerable rangeFix by version rangeDependents
com.fasterxml.jackson.core:jackson-databind2.22.0, 2.22.1, 2.22.2
  • 2.0.0 up to 2.18.11: fixed in 2.18.11
  • 2.19.0 up to 2.21.7: fixed in 2.21.7
  • 2.22.0 up to 2.22.3: fixed in 2.22.3
—
tools.jackson.core:jackson-databind3.2.0, 3.2.1, 3.2.2
  • 3.0.0 up to 3.1.7: fixed in 3.1.7
  • 3.2.0 up to 3.2.3: fixed in 3.2.3
—
Debian:12(1)
PackageVulnerable rangeFix by version rangeDependents
jackson-databind2.14.0+ds-1, 2.14.0+ds-2, 2.14.0-1, 2.14.0-1+deb12u1
  • every version on: no fix on record
—
Debian:13(1)
PackageVulnerable rangeFix by version rangeDependents
jackson-databind2.14.0+ds-1, 2.14.0+ds-1+deb13u1, 2.14.0+ds-2
  • every version on: no fix on record
—
Debian:14(1)
PackageVulnerable rangeFix by version rangeDependents
jackson-databind2.14.0+ds-1, 2.14.0+ds-2
  • every version on: no fix on record
—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 51× in last 30d)

Each row is a time one of our pipelines fetched, updated or re-scored this CVE. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. An arrow marks a change the record states ("CVSS v3 → 9.1"); EPSS and GHSA rows show the values recorded at that time, not what changed (EPSS values are rounded; hover one for the exact figures). Most recent first.

A repeat, a row identical to one the same pipeline wrote less than 10 seconds earlier, is not a separate refresh and is not counted. 1 repeat row among the latest 74 is merged into the row it repeats.

  1. 2026-11-01 16:36 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  2. 2026-11-01 07:37 UTCGHSA enrichmentGHSA-wv8q-qhhj-9h54 · GitHub severity HIGH · GitHub CVSS 7.5
  3. 2026-11-01 07:37 UTCEG score recompute
  4. 2026-10-31 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  5. 2026-10-30 16:35 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  6. 2026-10-29 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  7. 2026-10-28 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  8. 2026-10-27 17:29 UTCEG score recompute
  9. 2026-10-27 17:29 UTCVendor advisory
  10. 2026-10-27 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  11. 2026-10-26 16:33 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  12. 2026-10-25 16:34 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  13. 2026-10-25 13:51 UTCEG score recompute
  14. 2026-10-24 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  15. 2026-10-23 16:32 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  16. 2026-10-22 16:35 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  17. 2026-10-21 16:34 UTCEPSS rescoreEPSS 0.4% · 38th percentile
  18. 2026-10-20 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  19. 2026-10-19 17:04 UTCEG score recompute
  20. 2026-10-19 17:04 UTCVendor advisory
  21. 2026-10-19 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  22. 2026-10-18 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  23. 2026-10-18 03:00 UTCEG score recompute
  24. 2026-10-17 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  25. 2026-10-16 16:45 UTCEPSS rescoreEPSS 0.4% · 37th percentile
Show 48 more
  1. 2026-10-15 16:33 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  2. 2026-10-14 16:34 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  3. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  4. 2026-10-13 04:40 UTCEG score recompute
  5. 2026-10-12 16:35 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  6. 2026-10-12 14:45 UTCEG score recompute
  7. 2026-10-11 19:13 UTCEG score recompute
  8. 2026-10-11 16:30 UTCEG score recompute
  9. 2026-10-11 13:50 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  10. 2026-10-11 13:44 UTCEG score recompute
  11. 2026-10-11 12:59 UTCEG score recompute
  12. 2026-10-11 01:34 UTCEG score recompute
  13. 2026-10-10 20:00 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  14. 2026-10-10 03:05 UTCEG score recompute
  15. 2026-10-09 20:08 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  16. 2026-10-08 17:58 UTCEG score recompute
  17. 2026-10-08 17:14 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  18. 2026-10-08 06:56 UTCEG score recompute
  19. 2026-10-07 23:48 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  20. 2026-10-06 21:50 UTCEG score recompute
  21. 2026-10-06 15:18 UTCEPSS rescoreEPSS 0.4% · 37th percentile
  22. 2026-10-05 23:47 UTCEG score recompute
  23. 2026-10-05 17:44 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  24. 2026-10-05 01:43 UTCEG score recompute
  25. 2026-10-04 23:22 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  26. 2026-10-03 16:38 UTCEG score recompute
  27. 2026-10-02 18:34 UTCEG score recompute
  28. 2026-10-01 20:31 UTCEG score recompute
  29. 2026-10-01 19:51 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  30. 2026-09-30 22:19 UTCEG score recompute
  31. 2026-09-30 15:04 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  32. 2026-09-30 00:15 UTCEG score recompute
  33. 2026-09-29 00:28 UTCEG score recompute
  34. 2026-09-28 13:52 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  35. 2026-09-27 15:23 UTCEG score recompute
  36. 2026-09-27 13:49 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  37. 2026-09-26 17:19 UTCEG score recompute
  38. 2026-09-26 15:59 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  39. 2026-09-26 06:17 UTCEG score recompute
  40. 2026-09-24 20:55 UTCEG score recompute
  41. 2026-09-24 14:04 UTCEPSS rescoreEPSS 0.4% · 36th percentile
  42. 2026-09-24 02:21 UTCEG score recompute
  43. 2026-09-23 17:54 UTCEPSS rescoreEPSS 0.5% · 41st percentile
  44. 2026-09-23 15:20 UTCEG score recompute
  45. 2026-09-23 14:25 UTCEG score recompute
  46. 2026-09-23 03:27 UTCEG score recompute
  47. 2026-09-23 02:28 UTCEG score recomputeFirst assessed: 7.5 HIGH
  48. 2026-09-23 02:27 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-91776?
CVE-2026-91776 is a high-severity vulnerability; its CVE record was published on September 23, 2026. TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type…
When was the CVE record for CVE-2026-91776 published?
The CVE record for CVE-2026-91776 was published on September 23, 2026. That is the record's publication date; the vulnerability itself may have been made public earlier. EchelonGraph's copy of the record carries a last-modified date of September 24, 2026; the record at its source may have been updated since.
Is CVE-2026-91776 actively exploited?
CVE-2026-91776 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.5% probability of exploitation in the next 30 days (41st percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-91776?
CVE-2026-91776 has a CVSS base score of 7.5 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-91776?
A fix for CVE-2026-91776 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2026-91776 are linked in the Vendor Advisories panel on this page.

Dependency Blast Radius

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