CVE-2026-89140

MEDIUMPre-NVD 6.06.0
EchelonGraph scoreLOW confidence

This medium-severity CVE scores 6.0 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3% (24th 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: a secondary CVSS source
Trending — 3 sources updated this week
6.0EG
EchelonGraph verdictMonitorRemediate within your standard update timelines (the SSVC decision on this page).
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0.3%CVSS: 6.0Exploit: None knownExposed services: Not assessed

Upgrade to Temporal Server 1.30.8, 1.31.4, or 1.32.1, as appropriate for the deployed minor release line (from the CVE record's solution, Temporal Technologies Inc.) — apply it.

Temporal Server does not bind internal completion callbacks to the namespace that attached them, which allows an authenticated caller with write permission in one namespace to alter Scheduler V2 schedule state in another namespace. The callback address temporal://internal is reserved for callbacks that Scheduler V2 attaches to the Workflows it starts. In affected releases, any authenticated caller could attach a callback with that address to a Workflow start request, the address was exempt from the component.callbacks.allowedAddresses allowlist, and the History service delivered the callback to the component its token named, in whatever namespace that was, without authorizing the original caller there. When the forged completion matches an action a target schedule is running, the schedule records the action as completed while its Workflow still runs, which can defeat an overlap policy such as SKIP, and passes caller-controlled data to the next scheduled Workflow as its last completion result. A forged failure may also pause a schedule configured to pause on failure. A forgery requires the target namespace identifier, the schedule identifier, and the identity and timing of a running action. No disclosure of Workflow payloads or history was identified. Only namespaces that hold Scheduler V2 schedules can be targeted; Scheduler V2 is off by default, and existing Scheduler V2 schedules remain targets after the settings that create them are turned off.

CVSS v3
6.0
EG Score
6.0MEDIUMlow confidence
EG Risk
27
EG Risk 27/100

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed (value × EchelonGraph’s weight)
Severity60% × 45%
The EG Score, 6.0 of 10.
Exploitation0% × 40%
No KEV listing, EG-KEV tier or EPSS when EchelonGraph scored this CVE.
Automatability0% × 15%
CISA's BOD 26-04 default: no one has published Automatable for this CVE, and CISA treats it as “no” for a CVE not in KEV.
SSVC (CISA's decision table, applied by EchelonGraph): Track at low or medium mission impact; Track* at high (mission-essential systems).
Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from Vulnrichment. EchelonGraph applied CISA's decision table to them; CISA publishes SSVC inputs and the table, not a decision for each CVE.
Action: Upgrade to Temporal Server 1.30.8, 1.31.4, or 1.32.1, as appropriate for the deployed minor release line (from the CVE record's solution, Temporal Technologies Inc.). Apply it within your standard update timelines.
EPSS PROB
0.3%
EPSS %ILE
24th
KEV
Not listed

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

Upgrade to Temporal Server 1.30.8, 1.31.4, or 1.32.1, as appropriate for the deployed minor release line (from the CVE record's solution, Temporal Technologies Inc.). Apply it within your standard update timelines.

Exploitation none (no CISA value, KEV listing or exploit code on record) · Automatable no (CISA's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). EchelonGraph holds no SSVC assessment of this CVE from CISA: none of these inputs is from 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's BOD 26-04 default) · Technical impact total (CISA's BOD 26-04 default). Where an input reads “CISA's BOD 26-04 default”, no one has published it for this CVE, and CISA's implementation guidance says: “If “Automatable” and “Technical Impact” information items about a CVE ID are not available and the CVE ID is not in the KEV Catalog, CISA will treat its values as “no” and “total,” respectively, until CISA or a third party provides metadata about the CVE ID. CISA will always provide the Vulnrichment data for a CVE ID listed in the KEV Catalog.” 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 12, 2026

Last Modified

October 12, 2026

References (10)

Vendor Advisories for CVE-2026-89140(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 4× in last 7d / 4× 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. 2026-10-13 16:35 UTCEPSS rescoreEPSS 0.3% · 24th percentile
  2. 2026-10-12 19:26 UTCEG score recompute
  3. 2026-10-12 18:57 UTCEG score recomputeFirst assessed: 6.0 MEDIUM
  4. 2026-10-12 18:55 UTCMITRE cvelistV5first tracked

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Frequently asked(5)

What is CVE-2026-89140?
CVE-2026-89140 is a medium-severity vulnerability; its CVE record was published on October 12, 2026. Temporal Server does not bind internal completion callbacks to the namespace that attached them, which allows an authenticated caller with write permission in one namespace to alter Scheduler V2 schedule state in another namespace. The callback address temporal://internal is reserved for callbacks…
When was the CVE record for CVE-2026-89140 published?
The CVE record for CVE-2026-89140 was published on October 12, 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 12, 2026; the record at its source may have been updated since.
Is CVE-2026-89140 actively exploited?
CVE-2026-89140 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0.3% probability of exploitation in the next 30 days (24th percentile of EPSS-scored CVEs).
What is the CVSS score of CVE-2026-89140?
CVE-2026-89140 has a CVSS base score of 6.0 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-89140?
The CVE record's solution for CVE-2026-89140, written by its CNA Temporal Technologies Inc., names the fix: "Upgrade to Temporal Server 1.30.8, 1.31.4, or 1.32.1, as appropriate for the deployed minor release line." The vendor advisories EchelonGraph has for CVE-2026-89140 are linked in the Vendor Advisories panel on this page.

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