Security readout for executives and security teams
Plain-English summary
A Linux RxRPC flaw allows duplicate or delayed response packets to repeat part of secure connection setup after the connection state has advanced. It carries a CVSS 7.5 rating for remotely triggerable availability impact. The supplied sources do not document practical attack prerequisites, successful exploitation, or data compromise.
Executive priority
Treat this as a high-priority availability risk for externally reachable or operationally important Linux systems using RxRPC. Accelerate vendor-supported kernel updates after confirming exposure. Broad emergency action is not supported by the current evidence because active exploitation and deployment prerequisites are undocumented.
Technical view
RESPONSE packets were processed outside the intended RXRPC_CONN_SERVICE_CHALLENGING state, permitting late or duplicate packets to rerun response verification and security initialization. The fix checks connection state under state_lock, records secured status locally, and avoids an unlocked post-transition state check.
Likely exposure
Potential exposure exists on affected Linux kernels where RxRPC service functionality is present and network-reachable. The CVSS vector indicates network access, low complexity, no privileges, and no user interaction. The bundle does not establish whether RxRPC is enabled by default or provide an unambiguous affected-to-fixed version mapping.
Exploitation context
CISA KEV status is false, and the supplied sources provide no evidence of active exploitation or a public exploit. The documented consequence is availability loss; confidentiality and integrity impacts are scored as none.
Researcher notes
The security boundary is connection-state synchronization during service challenge handling. Review should focus on RESPONSE processing, locking around state validation, repeated initialization, and secured-work queuing. The source bundle identifies multiple stable commits but does not map them clearly to affected distributions or demonstrate a reproducible denial-of-service condition.
Mitigation direction
- Obtain the appropriate supported kernel update containing the vendor-provided RxRPC fix.
- Prioritize systems that use RxRPC or expose related services to untrusted networks.
- Consult the operating-system vendor for exact affected and fixed package versions.
- Apply network exposure reduction where RxRPC is unnecessary or cannot yet be updated.
Validation and detection
- Inventory running kernel versions across Linux hosts.
- Determine whether RxRPC functionality is present, used, and reachable from untrusted networks.
- Compare deployed kernels with vendor advisories and the referenced stable-branch commits.
- After updating, verify the running kernel includes the applicable fix.
- Monitor affected hosts for unexplained crashes, hangs, or RxRPC-related availability events.
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
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CVE-2026-31676 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
CVSS vector scores
1 official scoreWe 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:N/A:H3.93.6LinuxVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/a1a8efde03a40b6c658d580e96644d9b9a2a0d3aCVE reference, Linux
- https://git.kernel.org/stable/c/6c3a0fbdafef8316e34ae22333e317a341e737cdCVE reference, Linux
- https://git.kernel.org/stable/c/0afdfd4941c1b60a1f5c361760daa970edca60cdCVE reference, Linux
- https://git.kernel.org/stable/c/a6bcf8010af093fe04f7100562e9542ab7882585CVE reference, Linux
- https://git.kernel.org/stable/c/29b44d904dceb832be880def08b8cb17a0aba91cCVE reference, Linux
- https://git.kernel.org/stable/c/d0035e634dae83237ab7f5681eb52b2f65d0ceb8CVE reference, Linux
- https://git.kernel.org/stable/c/03fd2ef73cb4ffd0af100a95b634af54f474414eCVE reference, Linux
- https://git.kernel.org/stable/c/c43ffdcfdbb5567b1f143556df8a04b4eeea041cCVE reference, Linux
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.