Security readout for executives and security teams
Plain-English summary
SWUpdate’s web upload service can be remotely crashed without authentication. A malformed update upload, combined with carefully timed network delivery, can make the parser read beyond allocated memory. The documented impact is denial of service, potentially interrupting update operations or device availability; confidentiality or integrity impact is not established.
Executive priority
Prioritize remediation for externally reachable or operationally critical SWUpdate services. Although exploitation requires precise timing, no authentication is required and successful attacks can disrupt availability. Treat inaccessible or disabled upload endpoints as lower immediate risk, but confirm exposure rather than relying on assumed network isolation.
Technical view
The multipart parser in mongoose_multipart.c can underflow an integer in mg_http_multipart_continue_wait_for_chunk() when receive-buffer length enters a specific range. A crafted POST to /upload with a malformed boundary and controlled TCP timing can cause an out-of-bounds heap read extending toward a local IPC socket. CVSS 4.0 is 8.2, with high availability impact and high attack complexity.
Likely exposure
Exposure requires SWUpdate deployments that provide the vulnerable HTTP multipart upload handler, allow attackers to reach /upload, and lack the referenced fix. Internet-facing or broadly reachable management interfaces present greater risk. The supplied affected-version notation is ambiguous, so exact exposure should be confirmed against build provenance and vendor guidance.
Exploitation context
No active exploitation is established: the CVE is not listed as KEV in the supplied bundle, and no cited source states exploitation in the wild. Exploitation is unauthenticated and network-accessible but requires a malformed multipart request and controlled TCP stream timing, reflected by high attack complexity.
Researcher notes
The relevant weakness classes are out-of-bounds read (CWE-125) and integer underflow (CWE-191). Focus defensive review on buffer-length arithmetic, multipart-boundary state handling, partial TCP reads, and the referenced commit. The bundle does not establish code execution, data disclosure, affected named releases, or exploitation in the wild.
Mitigation direction
- Apply the vendor patch referenced by commit beee2dc0feef1cfe84f1aa6fc980e104b2e47a74.
- Confirm fixed release availability and supported upgrade guidance with the SWUpdate vendor.
- Restrict /upload access to trusted management networks until remediation is verified.
- Monitor the upload service for crashes, restarts, and malformed multipart requests.
Validation and detection
- Inventory SWUpdate builds and determine whether they contain the referenced patch commit.
- Verify whether the HTTP upload service and /upload route are enabled and network-reachable.
- Review access controls to confirm untrusted clients cannot reach the upload endpoint.
- Use safe regression testing to confirm malformed multipart input is rejected without service instability.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-125: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCWE-191: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2026-28525 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N——VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H2.24VulnCheckVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Base CVSS 3.1 score
6.8MediumVector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:N/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/sbabic/swupdate/commit/beee2dc0feef1cfe84f1aa6fc980e104b2e47a74CVE reference, VulnCheck · patch
- https://www.vulncheck.com/advisories/swupdate-integer-underflow-in-multipart-upload-parserCVE reference, VulnCheck · third-party-advisory
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.