CVE-2026-105937

HIGHPre-NVD 8.78.7
EchelonGraph scoreMEDIUM confidence

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

This high-severity CVE scores 8.7 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (15th percentile of EPSS-scored CVEs). No GitHub Security Advisory CVSS is on record for this CVE.

Triggered by: Headline CVSS from a secondary CVSS source
Sources: EPSS, a secondary CVSS source
Trending — 4 sources updated this week

Also known asEUVD-2026-107475 (ENISA EUVD) · GHSA-376p-82ph-3q76 (GitHub Security Advisories)Source: ENISA EUVD

8.7EG
EchelonGraph verdictPlan a fixRemediate within your standard update timelines (the SSVC decision on this page).
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0.2%CVSS: 8.7Exploit: None knownExposed services: Not assessed

The CVE record names the fixed release — apply it.

Apache Pulsar shadow topics (PIP-180) are topics that read the stored messages of a source topic from that topic's managed ledger. The source topic is selected by setting the reserved topic property PULSAR.SHADOW_SOURCE. The admin REST API accepts this property when creating a non-partitioned or partitioned topic and when updating the properties of an existing topic. On these paths the broker authorizes the caller only against the topic being created or updated. It does not authorize the caller against the source topic named in the property. The existing authorization for shadow topic configuration (the SHADOW_TOPIC topic policy on the source topic) is applied only to the source-side shadow topics admin API, not to these paths.

As a result, an authenticated user who is allowed to create topics or update topic properties in one tenant can bind a topic in that tenant to a persistent topic in any other tenant. With the default authorization provider, these operations require the tenant admin role for the user's own tenant. The user does not need any permission on the source topic, its namespace or its tenant. This impact analysis assumes that Pulsar has been configured with the default authorization provider. For custom authorization providers, the impact could be different.

The user can then consume from the shadow topic, using only permissions on their own topic, and receive retained messages that were published to the source topic in the other tenant. Exposure is limited to messages that are still retained and readable in the source topic's ledgers; messages protected with client-side end-to-end encryption cannot be decrypted without the encryption keys. A producer on the shadow topic can also register a new schema version under the source topic's schema, subject to the schema compatibility settings; existing schema versions are not replaced.

In addition, the shadow topic's managed ledger applies its own retention, trimming, offloading and deletion to the source topic's ledgers. This can permanently delete the source topic's ledger data from BookKeeper and from tiered storage, regardless of the source topic's own subscriptions and retention policy, including messages that have not yet been acknowledged. Deleting the shadow topic can also delete the source topic's ledgers. This data loss can also affect shadow topics that were configured intentionally by administrators.

This issue affects Apache Pulsar versions from 3.0.0 before 4.0.14 and from 4.1.0 before 4.2.5. Apache Pulsar 2.x releases do not contain the shadow topic implementation.

  • 4.0.x version users should upgrade to at least 4.0.14.
  • 4.1.x and 4.2.x version users should upgrade to at least 4.2.5.

Users operating versions prior to those listed above should upgrade to the aforementioned patched versions or newer versions.

The currently supported Apache Pulsar release lines are 4.0.x and 5.0.x. The supported versions schedule is available at https://pulsar.apache.org/contribute/release-policy/.

In the fixed versions, shadow topics are disabled by default and are controlled by the new broker configuration setting enableShadowTopics (default false). While it is disabled, the broker rejects creating shadow topics, setting the PULSAR.SHADOW_SOURCE property, and loading or replicating to existing shadow topics. Deployments that use shadow topics must set enableShadowTopics=true in the broker configuration of all brokers after upgrading; otherwise existing shadow topics will not be loaded. When shadow topics are enabled, binding a shadow topic to a source topic in a different tenant requires the superuser role. The fixed versions also prevent a shadow topic from deleting or trimming the ledgers and offloaded data of its source topic.

Affected versions provide no configuration option to disable shadow topics. Users who cannot upgrade immediately can reduce exposure by granting the tenant admin role only to trusted principals.

CVSS v3
8.7
EG Score
8.7HIGHmedium confidence
EG Risk
39
EG Risk 39/100

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)
Severity87% × 45%
Impact severity (EG Severity): CVSS 8.7 of 10. Never the KEV-floored or EPSS-lifted EG Score.
Exploitation0.2% × 40%
FIRST EPSS: the 30-day exploitation probability when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's SSVC Automatable value: no (Vulnrichment).
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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: The CVE record names the fixed release. Apply it within your standard update timelines.
EPSS PROB
0.2%
EPSS %ILE
15th
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 (8.7): severity, escalated by confirmed exploitation. This CVE's 8.7 is its impact severity (EG Severity), not escalated.

EG Severity
8.7 HIGHCVSS-B, impact only: no KEV listing, EPSS or EG-KEV tier raises it.a secondary CVSS source · CVSS v3.0 or v3.1
EG Likelihood
0.2% within 30 daysSource: FIRST EPSS. 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; Track* at high (mission-essential systems).CISA BOD 26-04: 14 days if the affected system is publicly exposed; Fix on system upgrade if it is not.Each input and its source: the SSVC and BOD 26-04 blocks below.

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

The CVE record names the fixed release. Apply it within your standard update timelines.

Exploitation none (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (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; Fix on system upgrade if it is not.

In CISA KEV no (CISA's KEV catalog) · Automatable no (CISA Vulnrichment) · Technical impact total (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

October 21, 2026

Last Modified

October 23, 2026

Advisory Details (1)

Auto-updated Oct 21, 2026
Fix named in the CVE record.
Web page

Pony Mail

https://lists.apache.org/thread.html/80foc311bwn839skc1p7fh89pgsrhyoj

Vendor Advisories for CVE-2026-105937(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 16× in last 7d / 16× 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.

  1. 2026-10-27 16:31 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  2. 2026-10-26 16:30 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  3. 2026-10-25 16:32 UTCEPSS rescoreEPSS 0.2% · 15th percentile
  4. 2026-10-25 14:55 UTCEG score recompute
  5. 2026-10-24 16:32 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  6. 2026-10-23 22:30 UTCEG score recompute
  7. 2026-10-23 22:29 UTCGHSA enrichmentGHSA-376p-82ph-3q76 · GitHub severity HIGH
  8. 2026-10-23 22:08 UTCEG score recompute
  9. 2026-10-23 22:07 UTCGHSA enrichmentGHSA-376p-82ph-3q76 · GitHub severity HIGH
  10. 2026-10-23 16:31 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  11. 2026-10-22 17:07 UTCEG score recompute
  12. 2026-10-22 17:06 UTCGHSA enrichmentGHSA-376p-82ph-3q76 · GitHub severity HIGH
  13. 2026-10-22 16:33 UTCEPSS rescoreEPSS 0.2% · 13th percentile
  14. 2026-10-21 19:27 UTCEG score recompute
  15. 2026-10-21 18:31 UTCEG score recomputeFirst assessed: 8.7 HIGH
  16. 2026-10-21 18:30 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-105937?
CVE-2026-105937 is a high-severity vulnerability; its CVE record was published on October 21, 2026. Apache Pulsar shadow topics (PIP-180) are topics that read the stored messages of a source topic from that topic's managed ledger. The source topic is selected by setting the reserved topic property PULSAR.SHADOWSOURCE. The admin REST API accepts this property when creating a non-partitioned or…
When was the CVE record for CVE-2026-105937 published?
The CVE record for CVE-2026-105937 was published on October 21, 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 October 23, 2026; the record at its source may have been updated since.
Is CVE-2026-105937 actively exploited?
CVE-2026-105937 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.2% probability of exploitation in the next 30 days (15th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-105937?
CVE-2026-105937 has a CVSS base score of 8.7 (a secondary CVSS source that NVD displays; NVD's own analysis pending).
How do I remediate CVE-2026-105937?
The CVE record for CVE-2026-105937 names the fix: "- 4.0.x version users should upgrade to at least 4.0.14." The vendor advisories EchelonGraph has for CVE-2026-105937 are linked in the Vendor Advisories panel on this page.

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