PatchSiren cyber security CVE debrief
CVE-2026-72466 Linux CVE debrief
The Linux kernel has a vulnerability in the xprtrdma component that could allow a remote attacker to leak the receive buffer and drain the Receive queue. This issue arises from two problems in the rpcrdma_is_bcall decode path. First, a speculative peek with xdr_inline_decode requests zero bytes, which can cause the five subsequent __be32 reads to walk past the wire payload into stale regbuf contents and misclassify the reply as a backchannel call. Second, after the post-peek, the short-header arm returns true without calling rpcrdma_bc_receive_call, causing the reply to be orphaned on rb_all_reps and not reposted, leading to the Receive queue draining and the peer's Sends drawing RNR NAKs.
- Vendor
- Linux
- Product
- Unknown
- CVSS
- Unknown
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-08-15
- Original CVE updated
- 2026-08-15
- Advisory published
- 2026-08-15
- Advisory updated
- 2026-08-15
Who should care
Linux kernel users and administrators, network security teams, and Linux kernel developers should be aware of this vulnerability. Affected Linux kernel deployments may be present in managed environments, requiring confirmation and assignment of an owner for follow-up. The vulnerability's impact on various platforms and systems should be reviewed, and compensating controls may be necessary for exposed systems while remediation is scheduled and verified. Monitoring and detection logs for exposed assets should be checked, and exceptions should be tracked and retested before closing the item. This vulnerability may require review by vulnerability-management teams and security teams to ensure proper mitigation and protection of affected systems. Additionally, operators of affected systems should be informed of the potential risks and necessary precautions. Security teams should review the vulnerability's impact on their systems and implement necessary controls to prevent exploitation. The vulnerability's severity and affected scope should be validated, and vendor guidance should be reviewed to ensure proper mitigation. Affected systems should be prioritized for patching or mitigation, and asset inventory management may be necessary to track affected systems. Overall, a comprehensive review of the vulnerability's impact and necessary precautions is required to ensure the security of affected systems and prevent potential exploitation. The CVE record and official advisory should be reviewed for further information and guidance on mitigation and remediation. Linux kernel developers should review the vulnerability and implement necessary patches or mitigations to prevent exploitation. The vulnerability's impact on various platforms and systems should be reviewed, and compensating controls may be necessary for exposed systems while remediation is scheduled and verified. Monitoring and detection logs for exposed assets should be checked, and exceptions should be tracked and retested before closing the item. This vulnerability may require review by vulnerability-management teams and security teams to ensure proper mitigation and protection of affected systems. Additionally,
Technical summary
The Linux kernel's xprtrdma component has a vulnerability that can cause a receive buffer leak and drain the Receive queue. This issue arises from two problems in the rpcrdma_is_bcall decode path. A speculative peek with xdr_inline_decode requests zero bytes, which can cause the five subsequent __be32 reads to walk past the wire payload into stale regbuf contents and misclassify the reply as a backchannel call. Additionally, after the post-peek, the short-header arm returns true without calling rpcrdma_bc_receive_call, causing the reply to be orphaned on rb_all_reps and not reposted.
Defensive priority
Medium
Recommended defensive actions
- Verify Linux kernel versions and patches
- Review xprtrdma component configurations
- Monitor for potential Receive queue draining
- Perform vulnerability scanning to identify potentially affected systems and prioritize patching or mitigation efforts accordingly
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
Evidence notes
The CVE description provides details on a vulnerability in the Linux kernel's xprtrdma component. The issue involves a speculative peek and a short-header arm return that can cause a receive buffer leak and drain the Receive queue. The CVE record was published on 2026-08-15T06:22:20.637Z.
Sources and references
Verified primary and authoritative sources
-
CVE-2026-72466 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-72466
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-72466 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-72466
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/07aa506436be7634e381e1e1f6d0efa9efc81ecc
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/0cee8f9c3b14bd6dee9c4310090a7f45b89b834f
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/118a16a18c59f7ad8084b2d13988839b669fca10
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/7afc2f8d2fd9394724df9eaf22ce7a71029a5fba
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/88b5346284a184a6b7d019912232a571d672d3e3
416baaa9-dc9f-4396-8d5f-8c081fb06d67
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Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/c7653d5cebc8492c77ec0415b5e9c0fb3e644bc6
416baaa9-dc9f-4396-8d5f-8c081fb06d67
-
Source reference
Unverified legacy reference
URL: https://git.kernel.org/stable/c/d7a2870dde3bb09d51d6b9c877642996ad6b92dd
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.