CVE Intelligence
Medium Memory corruption

CVE-2026-116188 — rclone serve s3 1.75.0 before 1.75.2 Memory Limit Bypass via Multipart Overflow

rclone serve s3 versions 1.75.0 before 1.75.2 contain an integer overflow vulnerability in multipart reorder-memory accounting that bypasses the configured buffer limit. Attackers can open two concurrent current-part PUT requests declaring huge lengths to wrap the signed int64 counter and retain out-of-order parts in memory, exhausting the host.

Published Oct 25, 2026 · Updated Oct 28, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: VulnCheck

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.3% (30-day exploitation probability)+3
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.25%
ahead of 17% of scored CVEs · Oct 29, 2026
Affects
Rclone
Rclone
CVSS base
5.3
Medium · 3 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Rclone Rclone).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Rclone Rclone ≥ 1.75.0 and < 1.75.2 Vulnerable CVE Program (cve.org) e CISA ADP
Rclone Rclone ≥ 1.75.0 and < 1.75.2 Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

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

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
6.9 CVSS 4.0 Medium — — disclosure@vulncheck.com via NIST National Vulnerability Database
6.9 CVSS 4.0 Medium — — VulnCheck via CVE Program (cve.org) e CISA ADP
5.3 CVSS 3.1 Medium 3.9 1.4 disclosure@vulncheck.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
5.3 CVSS 3.1 Medium — — VulnCheck via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-190 · Integer Overflow or Wraparound

Other CVEs with this weakness →

EPSS over time FIRST

Oct 26, 2026 → Oct 29, 2026 · 4 reading(s) · max 0.27%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · rclone/rclone
    Oct 28, 2026 · NIST National Vulnerability Database
  • Source status changed · Undergoing Analysis → Analyzed
    Oct 28, 2026 · NIST National Vulnerability Database
  • Source status changed · Awaiting Analysis → Undergoing Analysis
    Oct 28, 2026 · NIST National Vulnerability Database
  • Source status changed · Received → Awaiting Analysis
    Oct 26, 2026 · NIST National Vulnerability Database
  • Affected products added · rclone/rclone
    Oct 25, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 25, 2026
  • CVSS changed · 5.3
    Oct 25, 2026 · NIST National Vulnerability Database
  • Source status changed · → Received
    Oct 25, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 25, 2026 · Alertas do Telegram
  • CVE published
    Oct 25, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 25, 2026 – Oct 26, 2026
  • 1× Official description updated · Oct 25, 2026 – Oct 25, 2026

References

4 on the record

Elsewhere on this site

Rclone
every CVE for this vendor
Memory corruption
same class
CWE-190
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-116196 Rclone before v1.75.2 B2 Credential Leak on Redirect via --b2-download-url 5d
  • CVE-2026-116190 rclone v1.56.0 before v1.75.2 WebDAV Credential Header Leak on Redirect 5d
  • CVE-2026-116189 rclone 1.55.0 before 1.75.2 selfupdate Signature Verification Bypass via SHA256SUMS 5d
  • CVE-2026-116191 Rclone before 1.75.2 Path Traversal via serve webdav MKCOL 5d
  • CVE-2026-116192 rclone from 1.37 before 1.74.2 SSRF via --rc-serve scheme-relative remote roots 5d
  • CVE-2026-116193 Rclone 1.64.0 before 1.75.2 serve webdav Authentication Bypass via OPTIONS Requests 5d

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-116188 is "rclone serve s3 1.75.0 before 1.75.2 Memory Limit Bypass via Multipart Overflow", rated Medium. It affects Rclone (Rclone); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. EPSS 0.25% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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