CVE Intelligence
Unknown

CVE-2026-89543 — sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir

In the Linux kernel, the following vulnerability has been resolved: sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir Normal client creation goes through rpc_setup_pipedir(), which records clnt->pipefs_sb, but the mount-event path in __rpc_clnt_handle_event() calls rpc_setup_pipedir_sb() directly and never refreshes that field. The umount path also removes the directory without clearing clnt->pipefs_sb. After a late pipefs mount or any remount, rpc_clnt_remove_pipedir() compares the current superblock against a stale pipefs_sb pointer and skips cleanup, leaving pipefs dentries whose inode private data still points at a freed rpc_clnt, leading to a potential use-after-free during subsequent rpc_info_open() or rpc_show_info() calls. Fix this by properly updating clnt->pipefs_sb upon mount events and clearing it during unmount or failure paths.

Published Sep 11, 2026 · Updated Oct 21, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP, GitHub Security Advisories · CNA: Linux

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.2% (30-day exploitation probability)+2

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.21%
ahead of 11% of scored CVEs · Oct 27, 2026
Affects
Linux
Linux
CVSS base
—
Score not published yet.

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
  2. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  3. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Linux Linux version 1cdb52ffd6600a37bd355d8dce58ecd03e55e618≥ 6.6.3 and < 6.6.160≥ cc2e7ebbeb1d0601f7f3c8d93b78fcc03a95e44a and < f99fedfd1dbffe8d20b421c9a7d4655a135d4fcdversion 6.7≥ 6.5.13 and < 6.6≥ 6.1.64 and < 6.2≥ 5.15.140 and < 5.16≥ 5.10.202 and < 5.11
and 11 more ≥ 5.4.280 and < 5.5≥ 4.19.318 and < 4.20≥ bfca5fb4e97c46503ddfc582335917b0cc228264 and < 59527bbfb1eabdb28e95e7c725886cc2c2899cb3version 7749fd2dbef72a52b5c9ffdbf877691950ed4680version 194454afa6aa9d6ed74f0c57127bc8beb27c20dfversion dedf2a0eb9448ae73b270743e6ea9b108189df46version 7d61d1da2ed1f682c41cae0c8d4719cdaccee5c5version 17866066b8ac1cc38fb449670bc15dc9fee4b40a≥ bfca5fb4e97c46503ddfc582335917b0cc228264 and < 932a8cf6abb2b2f8677b79153a823108d8861fe2≥ bfca5fb4e97c46503ddfc582335917b0cc228264 and < cdf7a233cb94774b0e7df42d9157077983f5022c≥ bfca5fb4e97c46503ddfc582335917b0cc228264 and < e769fcde3cc73e847b1eb3acd40c04a291cb0c0c
Vulnerable CVE Program (cve.org) e CISA ADP

EPSS over time FIRST

Oct 15, 2026 → Oct 27, 2026 · 12 reading(s) · max 0.21%

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Not enough vector or weakness data: use the affected application’s logs as a starting point.
application logs

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products removed · 2
    Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
  • Affected products added · linux/linux
    Oct 21, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Source status changed · → Received
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 11, 2026 · Linux

Source activity

Repeated readings are counted rather than listed.

  • 2× References added · Oct 19, 2026 – Oct 21, 2026
  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

7 on the record

Elsewhere on this site

Linux
every CVE for this vendor

Related CVEs (same products)

  • CVE-2026-99216 Drivers: hv: Don't reset VMBus connection state on error/exit paths 15m
  • CVE-2026-99214 drm/vc4: hdmi: Move packet RAM enable to PM runtime 15m
  • CVE-2026-99213 vsock: treat TCP_CLOSING as once-established 15m
  • CVE-2026-99212 net/rds: don't let the rdma_cm destroy an id RDS still owns on route failure 15m
  • CVE-2026-99211 netlink: reset skb headers before unicast and multicast filtering 15m
  • CVE-2026-99210 accel/rocket: clear rdev on device init failure 15m

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No CVSS score published by NVD, the CNA, CISA or GitHub so far.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No CWE classification.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-89543 is "sunrpc: fix use-after-free in __rpc_clnt_handle_event and __rpc_clnt_remove_pipedir", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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