CVE-2026-72466: xprtrdma: Fix bcall rep leak and unbounded peek
- Is it exploited?
Not on CISA's list. CISA has not added it to the Known Exploited Vulnerabilities catalog as of . If CISA adds it, this page shows it as known exploited.
- How likely is exploitation in the next 30 days?
- 0.7%
EPSS score, percentile 54.4 of all scored records. A probability estimated by FIRST, not a report of exploitation.
- How severe?
- 9.8 Critical
CVSS v3.1 base score, given by the CNA
- What should I do?
CISA has set no required action, because the vulnerability is not in KEV.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- 4.14
Unaffected before 4.14; 5.15.212; 6.1.178; 6.6.145; 6.12.97; 6.18.40; and 2 more
Source: CISA KEV 2026.10.29, as of ; FIRST EPSS, as of ; CVE List, as of . About the data.
What to do
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
This summary is based on the CVE record as of . Check the vendor's advisory before you act: affected versions and fixes can change.
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | from 41c8f70f5a3d to before 0cee8f9c3b14 |
| Affected | from 41c8f70f5a3d to before 7afc2f8d2fd9 |
| Affected | from 41c8f70f5a3d to before 88b5346284a1 |
| Affected | from 41c8f70f5a3d to before 07aa506436be |
| Affected | from 41c8f70f5a3d to before d7a2870dde3b |
| Affected | from 41c8f70f5a3d to before 118a16a18c59 |
| Affected | from 41c8f70f5a3d to before c7653d5cebc8 |
Versions not listed are: unaffected.
| Status | Versions |
|---|---|
| Affected | 4.14 |
| Unaffected | before 4.14 |
| Unaffected | 5.15.212 |
| Unaffected | 6.1.178 |
| Unaffected | 6.6.145 |
| Unaffected | 6.12.97 |
| Unaffected | 6.18.40 |
| Unaffected | 7.1.5 |
| Unaffected | 7.2 |
Versions not listed are: affected.
Versions the record lists as unaffected: 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2.
Source: CVE List, as of . About the data.
About this vulnerability
In the Linux kernel, the following vulnerability has been resolved: xprtrdma: Fix bcall rep leak and unbounded peek rpcrdma_is_bcall() decodes a reply's first words to decide whether the frame is a backchannel call. Two issues in that decode path let a short or malformed reply leak the receive buffer and drain the Receive queue. First, the speculative peek p = xdr_inline_decode(xdr, 0);…
Summary: CVE record, as of .
- CISA has not added CVE-2026-72466 to its Known Exploited Vulnerabilities (KEV) catalog, as of 29 Oct 2026.
- The CVE record was published on 15 Aug 2026.
- The CVE record carries a CVSS v3.1 base score of 9.8 (Critical), given by its CNA.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 0.7% (percentile 54.4), as of 29 Oct 2026. EPSS is a statistical estimate, not a report of exploitation.
- CISA's SSVC assessment in the CVE record: exploitation none, automatable yes, technical impact total.
Source: CISA KEV 2026.10.29, as of ; CVE List, as of ; FIRST EPSS, as of . About the data.
Description
xprtrdma: Fix bcall rep leak and unbounded peek
In the Linux kernel, the following vulnerability has been resolved: xprtrdma: Fix bcall rep leak and unbounded peek rpcrdma_is_bcall() decodes a reply's first words to decide whether the frame is a backchannel call. Two issues in that decode path let a short or malformed reply leak the receive buffer and drain the Receive queue. First, the speculative peek p = xdr_inline_decode(xdr, 0); /* five p++ reads follow */ asks xdr_inline_decode() for zero bytes, which returns xdr->p without consulting xdr->end. The five subsequent __be32 reads can then walk up to 20 bytes past the wire payload into stale regbuf contents and misclassify the reply as a backchannel call. Second, after the post-peek p = xdr_inline_decode(xdr, 3 * sizeof(*p)); if (unlikely(!p)) return true; the short-header arm returns true without calling rpcrdma_bc_receive_call(). The contract with the caller is that a true return transfers ownership of rep to the backchannel path: rpcrdma_reply_handler() if (rpcrdma_is_bcall(r_xprt, rep)) return; /* bare return, skips out_post */ ... out_post: rpcrdma_post_recvs(r_xprt, credits + ...); Because rpcrdma_bc_receive_call() never ran, no one took rep, but rpcrdma_reply_handler still bare-returns past rpcrdma_rep_put() and rpcrdma_post_recvs(). The rep, with its persistently DMA-mapped receive buffer, is orphaned on rb_all_reps and freed only at transport teardown. This completion reposts nothing, so its slot is reclaimed only when a later forward-channel reply reaches out_post and rpcrdma_post_recvs() allocates a fresh rep to backfill; absent that traffic the Receive queue drains and the peer's Sends draw RNR NAKs. Fix by consulting xdr->end after the zero-length peek so the five __be32 reads cannot run unless 20 bytes of wire payload remain. A byte-precise comparison against xdr->end is required because a non-4-aligned receive rounds the stream's word count up past the true payload. Also return false from the short-header arm so the reply falls through the normal out_norqst cleanup chain (rpcrdma_rep_put() plus rpcrdma_post_recvs()).
Source: CVE List, as of . About the data.
Timeline
| Date | Event |
|---|---|
| CVE record published | |
| CVE record last updated |
References
7
Known exploited Linux vulnerabilities
- CVE-2026-46300: Linux Kernel Missing Initialization of a Variable Vulnerability
- CVE-2025-39682: Linux Kernel Improper Check for Unusual or Exceptional Conditions Vulnerability
- CVE-2025-39964: Linux Kernel Race Condition Vulnerability
- CVE-2026-53266: Linux Kernel Out-of-Bounds Write Vulnerability
- CVE-2026-53362: Linux Kernel Unspecified Vulnerability