Self-hosted ServiceNow operators inherit three unauthenticated CVSS 10.0 flaws to patch themselves
ServiceNow fixed its own hosted fleet on August 27 and handed the same update to partners and self-hosted customers, whose unauthenticated GraphQL and SQL exposure stays open until someone on staff installs it.
The Watch · Security desk
What happened
- ServiceNow's August 27, 2026 advisory covers four ServiceNow AI Platform flaws, three of them rated CVSS 10.0 and reachable, in certain circumstances, by an unauthenticated attacker.
- CVE-2026-18885 is a code injection in the GraphQL Composite Data API that lets an unauthenticated user run arbitrary code and read or alter instance data.
- CVE-2026-74820 is a SQL injection reached through a dynamic schema ORDER BY clause, giving an unauthenticated caller arbitrary SQL against the instance's underlying database.
- ServiceNow updated its hosted instances itself and passed the same update to partners and self-hosted customers, who have to install it on their own schedule.
- The company says it is not currently aware of malicious exploitation against ServiceNow instances and is telling customers to apply the updates promptly.
Why it matters
- Who's exposed exposure A platform in use at 85 percent of the Fortune 500, wired into core enterprise workflows, now has unauthenticated write access to instance data sitting behind whatever patch queue each self-hosted operator runs.
- Who has to decide decision Every self-hosted operator has to price an out-of-band change window on the system its workflows depend on against leaving a no-privilege, no-interaction path open.
- What it limits constraint With nothing in KEV and NIST enrichment narrowed, triage teams have no independent severity read to argue with the vendor's, and no federal deadline to borrow as internal leverage.
- What doesn't add up contradiction The two publishers disagree on whether the 8.7 sandbox escape needs credentials, which decides whether it is an internet-facing risk or a post-access one.
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CVE-2026-18886 is the one both write-ups treat as an afterthought. ServiceNow describes it as improper access control in the system configuration image upload processor, letting an unauthenticated user create or modify instance data and escalate privileges [4]. The three maximum-severity records share one vector string, and the tail of it matters more than the 10.0: SC:H/SI:H/SA:H, meaning high impact to the systems connected to the vulnerable component, not only the component [6]. That is scoring language for blast radius, and this platform integrates AI into core enterprise workflows and runs more than 100,000 enterprise AI apps at 85 percent of the Fortune 500 [16].
The scores are ServiceNow's own. It is the CVE Numbering Authority for its products [12], and since April 15, 2026 NIST has enriched only vulnerabilities in CISA's Known Exploited Vulnerabilities catalog, those affecting federal government software, or those designated critical under Executive Order 14028 [13]. None of the four was in the catalog as of August 28, so the vendor's rating is the only assessment on record [14]. Read it against July: ServiceNow scored CVE-2026-6875 at 9.5 with every metric identical to the new three except attack complexity, which it set to high [11]. The half point is attack complexity and nothing else [19]. AC:L on the new three is the vendor saying no special conditions are required.
July is why that metric carries weight. Searchlight Cyber reported CVE-2026-6875 on April 1, 2026, and ServiceNow published on July 13, 103 days later [9][20]. Days after that advisory, Defused said it was observing in-the-wild exploitation, then corrected itself: the captured payload matched Searchlight's published proof of concept [8]. ServiceNow said it had seen no evidence the activity involved instances it hosts [10]. What is public, then, is a payload derived from a public PoC landing on reachable instances. Malicious operator activity stays unconfirmed.
Forty-five days separate the two advisories [21]. The pattern around this platform is consistent. In 2024, attackers chained CVE-2024-4879, CVE-2024-5178 and CVE-2024-5217 with publicly available exploits to breach private firms and government agencies worldwide [17]. Last month, according to BleepingComputer, ServiceNow privately disclosed an incident in which researchers or customer-led research used an unauthenticated access flaw in a vulnerable API endpoint to query data from customer instances [18]. Unauthenticated reach into instance data is the recurring shape here.
One detail for anyone on the Australia release train. The record for CVE-2026-18886 marks any version before Australia Patch 5 with a status of unknown, while the records for the other three mark that same version affected, and all four default to unaffected for releases the list does not name [15]. On that branch, the advisory does not tell you whether the image upload flaw reaches you.
What to watch
- A KEV listing for any of the three would restore NIST enrichment and put a federal remediation date on the clock.
- A public PoC for CVE-2026-18885 or CVE-2026-74820, given that the 2024 ServiceNow chain ran on publicly available exploits.
- Whether ServiceNow resolves the unknown status on Australia Patch 5 in the CVE-2026-18886 record.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence66
- Adoption32
- Hype gap+27
- Incentives68
- Confidence70
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
ServiceNow published an advisory on August 27, 2026 covering four security flaws in the ServiceNow AI Platform, three of them rated 10.0 on CVSS and exploitable, in certain circumstances, by an unauthenticated attacker.
- [2]
ServiceNow deployed a security update to hosted instances and provided the update to its partners and self-hosted customers, leaving organisations that run their own instances to apply the fixes themselves.
- [3]
CVE-2026-18885 (CVSS 10.0) is a code injection vulnerability in the GraphQL Composite Data API that could enable an unauthenticated user to execute arbitrary code and gain access to, or modify, instance data.
- [4]
CVE-2026-18886 (CVSS 10.0) is an improper access control vulnerability in the system configuration image upload processor that could enable an unauthenticated user to create or modify instance data, resulting in privilege escalation.
- [5]
CVE-2026-74820 (CVSS 10.0) is a SQL injection vulnerability reached through a dynamic schema ORDER BY clause that could enable an unauthenticated user to execute arbitrary SQL statements against the instance's underlying database.
- [6]
The three maximum-severity flaws share the vector CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H, describing a network-reachable attack of low complexity requiring no privileges and no user interaction, with high impact to confidentiality, integrity and availability in both the vulnerable component and the systems connected to it.
- [7]
ServiceNow said: "We are not currently aware of malicious exploitation against ServiceNow instances. We recommend customers promptly apply appropriate updates or upgrade to a patched release if they have not already done so."
- [8]
Threat intelligence firm Defused said days after the July advisory that it was observing in-the-wild exploitation of CVE-2026-6875, then issued a correction stating that the captured payload matched Searchlight Cyber's published proof-of-concept exploit.
- [9]
CVE-2026-6875 is a pre-authentication sandbox escape in the same platform; Searchlight Cyber reported it to ServiceNow on April 1, 2026, and ServiceNow published the advisory for it on July 13.
- [10]
A ServiceNow spokesperson said that based on its investigation to date, it had not observed evidence that the reported CVE-2026-6875 activity was related to instances that ServiceNow hosts.
- [11]
ServiceNow scored CVE-2026-6875, the sandbox escape reported exploited in July, at 9.5 under the same version of the scoring system, with every metric identical to the three new maximum-severity flaws except attack complexity, which it set to high.
- [12]
The 10.0 ratings are ServiceNow's own; the company is the CVE Numbering Authority for its products.
- [13]
Since April 15, 2026, NIST has enriched only vulnerabilities that appear in CISA's Known Exploited Vulnerabilities catalog, affect federal government software, or are designated critical under Executive Order 14028.
- [14]
None of the four flaws appeared in CISA's Known Exploited Vulnerabilities catalog as of August 28, 2026, leaving ServiceNow's ratings as the only severity assessment on record.
- [15]
The record for CVE-2026-18886 marks "Any version before Australia Patch 5" with a status of unknown, where the records for the other three mark the same version as affected; all four set a default product status of unaffected, so a release the list does not name falls outside the affected set.
- [16]
The ServiceNow AI Platform, formerly the Now Platform, is an enterprise Platform-as-a-Service that helps integrate AI into core enterprise workflows and powers more than 100,000 enterprise AI apps at 85% of all Fortune 500 companies.
- [17]
Two years ago, threat actors chained three ServiceNow flaws (CVE-2024-4879, CVE-2024-5178 and CVE-2024-5217) using publicly available exploits to breach private firms and government agencies worldwide in data theft attacks.
- [18]
ServiceNow privately disclosed a security incident last month in which security researchers or customer-led research used an unauthenticated access flaw via a vulnerable API endpoint to query data from customer instances.
- [19]
The 0.5-point gap between ServiceNow's 9.5 for CVE-2026-6875 and the 10.0 given to the three new flaws is attributable entirely to the attack complexity metric.
- [20]
103 days passed between Searchlight Cyber reporting CVE-2026-6875 on April 1, 2026 and ServiceNow publishing the advisory on July 13, 2026.
- [21]
45 days separate the July 13, 2026 advisory for CVE-2026-6875 and the August 27, 2026 advisory covering the four new flaws.
- [22]
The Hacker News lists CVE-2026-6876 (CVSS 8.7) as a sandbox escape in the Now Platform that could allow an unauthenticated user to execute arbitrary code.
- [23]
BleepingComputer describes CVE-2026-6876 as a high-severity sandbox escape affecting the same platform that could let attackers with basic privileges gain remote code execution on targeted systems.
Sources
2 independent publishers whose own reporting we read for this story.
- bleepingcomputer.comServiceNow warns of three max severity security vulnerabilities
1 article · August 28, 2026
- thehackernews.comThree CVSS 10.0 ServiceNow Flaws Could Let Unauthenticated Attackers Execute Code and SQL
2 articles · August 28, 2026
Topics and entities
Topics
- Vulnerability Disclosure
- Enterprise SaaS Security
- Self-Hosted vs Vendor-Hosted Risk
- CVSS Severity Scoring
- Patch And Redeploy Latency
Entities
- Defused
- ServiceNow
- ServiceNow AI Platform
- Searchlight Cyber
- CISA Known Exploited Vulnerabilities Catalog
- National Institute of Standards and Technology
- Executive Order 14028