Security readout for executives and security teams
Plain-English summary
OpenClaw before 2026.2.25 could process the same valid Nextcloud Talk webhook more than once. A replayed webhook may duplicate inbound message handling, creating data integrity issues or service disruption rather than direct data theft.
Executive priority
Treat as a moderate operational integrity issue. Patch affected OpenClaw webhook-processing systems in the normal security update cycle, faster where duplicate message processing could affect workflows or availability.
Technical view
The issue is CWE-294: missing durable replay suppression for signed Nextcloud Talk webhook events. Valid previously signed requests can be replayed and accepted, causing duplicate processing. CVSS is 6.5 with network attack vector, no privileges, no user interaction, low integrity and availability impact.
Likely exposure
Exposure is likely limited to deployments running OpenClaw before 2026.2.25 with Nextcloud Talk webhook integration enabled. The affected-version metadata is sparse, so confirm against vendor guidance.
Exploitation context
The provided sources do not show CISA KEV listing or confirmed active exploitation. Exploitation requires access to a valid signed webhook request that can later be replayed.
Researcher notes
The source bundle supports OpenClaw before 2026.2.25, CWE-294, CVSS 6.5, and a patch reference. It does not provide proof of exploitation in the wild or detailed affected CPE coverage.
Mitigation direction
- Upgrade OpenClaw to 2026.2.25 or later.
- Review the GitHub advisory and patch commit for vendor-confirmed remediation details.
- Prioritize systems processing Nextcloud Talk webhooks from internet-reachable endpoints.
- Monitor for duplicate inbound message processing until patched.
- If exposure is uncertain, follow current OpenClaw vendor guidance.
Validation and detection
- Inventory OpenClaw deployments and record exact versions.
- Confirm whether Nextcloud Talk webhook handling is enabled.
- Review logs for repeated identical webhook events or duplicate inbound messages.
- Verify patched deployments durably suppress replayed webhook events.
- Document any compensating controls and remaining unpatched instances.
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-294: 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-2026-28449 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
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L3.92.5VulnCheckCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N——VulnCheckVulnerability scoring details
Base CVSS 4.0 score
6.3MediumVector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
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
- GitHub Security Advisory (GHSA-r9q5-c7qc-p26w)CVE reference, VulnCheck · vendor-advisory
- Patch CommitCVE reference, VulnCheck · patch
- VulnCheck Advisory: OpenClaw < 2026.2.25 - Webhook Replay Attack via Missing Durable Replay SuppressionCVE 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.
Authentication Bypass by Capture-replay
Authentication Bypass by Capture-replay represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.