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NVD / CVE Program· CNA Linux

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

Noroxi assessment

Priority: Monitor (action score 0/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
  • Fixed version: Linux Linux 1a713814e0580f946196bca5e340b37991c6e8bf, 4.20, 5.11.
  • Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

Low priority for now. Upgrade to Linux Linux 1a713814e0580f946196bca5e340b37991c6e8bf, 4.20, 5.11 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

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.

—No exploit Fix available
Published
Sep 11, 2026
Updated
Oct 30, 2026
EPSS
0.2% · 11th percentile
CWE
—

Report tools

JSON

Action score

0

Monitor

Low priority for now.

CVSS
0 / 40 · —
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

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Noroxi analysis

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 17866066b8ac1cc38fb449670bc15dc9fee4b40a, 7d61d1da2ed1f682c41cae0c8d4719cdaccee5c5, dedf2a0eb9448ae73b270743e6ea9b108189df46, 194454afa6aa9d6ed74f0c57127bc8beb27c20df, 1cdb52ffd6600a37bd355d8dce58ecd03e55e618, 6.7affected
    • 7749fd2dbef72a52b5c9ffdbf877691950ed4680 and later · before 1a713814e0580f946196bca5e340b37991c6e8bfaffected · git
    • cc2e7ebbeb1d0601f7f3c8d93b78fcc03a95e44a and later · before f99fedfd1dbffe8d20b421c9a7d4655a135d4fcdaffected · git
    • bfca5fb4e97c46503ddfc582335917b0cc228264 and later · before 59527bbfb1eabdb28e95e7c725886cc2c2899cb3affected · git
    • bfca5fb4e97c46503ddfc582335917b0cc228264 and later · before e769fcde3cc73e847b1eb3acd40c04a291cb0c0caffected · git
    • bfca5fb4e97c46503ddfc582335917b0cc228264 and later · before cdf7a233cb94774b0e7df42d9157077983f5022caffected · git
    • bfca5fb4e97c46503ddfc582335917b0cc228264 and later · before 932a8cf6abb2b2f8677b79153a823108d8861fe2affected · git
    • 6.1.64 and later · before 6.1.191affected · semver
    • 6.6.3 and later · before 6.6.160affected · semver
    • 4.19.318 and later · before 4.20affected · semver

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxfrom 0—
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.2.6-17.2.6-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation
    40Plan
  • CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment
    40Plan
  • CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()
    40Plan

Published before and after this one in the same product

  • ← EarlierCVE-2026-89541Sep 11, 2026 · SUNRPC: harden gss_unwrap_resp_priv length checks
    39Monitor
  • ← EarlierCVE-2026-89542Sep 11, 2026 · SUNRPC: harden gss_krb5_unwrap_v2 against short tokens
    39Monitor
  • Later →CVE-2026-89544Sep 11, 2026 · SUNRPC: fix gssx_dec_option_array error path bugs
    30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux1a713814e0580f946196bca5e340b37991c6e8bfVendor (CNA)
Linux Linux4.20Vendor (CNA)
Linux Linux5.11Vendor (CNA)
Linux Linux5.16Vendor (CNA)
Linux Linux5.5Vendor (CNA)
Linux Linux59527bbfb1eabdb28e95e7c725886cc2c2899cb3Vendor (CNA)
Linux Linux6.1.191Vendor (CNA)
Linux Linux6.6Vendor (CNA)
Linux Linux6.6.160Vendor (CNA)
Linux Linux932a8cf6abb2b2f8677b79153a823108d8861fe2Vendor (CNA)
Linux Linuxcdf7a233cb94774b0e7df42d9157077983f5022cVendor (CNA)
Linux Linuxe769fcde3cc73e847b1eb3acd40c04a291cb0c0cVendor (CNA)
Linux Linuxf99fedfd1dbffe8d20b421c9a7d4655a135d4fcdVendor (CNA)
debian:linux6.12.111-1 · Debian:13Package registry (OSV)
debian:linux-6.126.12.111-1~deb12u1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

All national notices →

Technical details

No CVSS vector for this record, so attack conditions can't be derived.

Weakness class (CWE)

—

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. Fix✗ → ✓

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References

Show all references (5 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records