CVE-2026-89565 — ipip: fix skb leak in collect_md mode when metadata_dst allocation fails
In the Linux kernel, the following vulnerability has been resolved: ipip: fix skb leak in collect_md mode when metadata_dst allocation fails In collect_md mode ipip_tunnel_rcv() returns 0 without freeing the skb when ip_tun_rx_dst() fails to allocate the metadata_dst. ipip_rcv() and mplsip_rcv() are registered as xfrm_tunnel handlers, so tunnel4_rcv() and tunnelmpls4_rcv() read the zero return as "the packet has been consumed" and do not free it either. The skb is leaked. The other tunnel drivers all dispose of the packet at this point: ip6_tunnel.c jumps to its drop label, ip_gre.c and ip6_gre.c return PACKET_REJECT, which makes gre_rcv() free the skb. Only ipip returns 0. Jump to the existing drop label instead. It frees the skb and still returns 0, so the packet keeps being reported as consumed, which is what we want here: the outer header has already been pulled, and neither the remaining handlers nor an ICMP unreachable have any use for it. Triggering this needs an ipip or mplsip tunnel in collect_md mode and an atomic allocation failure, which is why it has gone unnoticed.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+1
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.
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.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < 1909df2d066424767429e13053eb9701263430ef≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < c4dc23de4cc75e4e304170b31bb8aeeacd5cb990≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < 6d8c5b266d0035a061573843a7243be068eb6118≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < 31e4be21dacee49395013caae28576484a049a4f≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < fd01f1a3ed4a189a784654f7c69eb565872f2e12≥ cfc7381b3002756b1dcada32979e942aa3126e31 and < 6776efe4a52f289a3fc18f8adf19b035a7d8e1bbversion 4.9 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 15, 2026 → Oct 22, 2026 · 7 reading(s) · max 0.17%
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.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Received
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× References added · Oct 19, 2026 – Oct 19, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/1909df2d066424767429e13053eb9701263430ef
- git.kernel.org/stable/c/31e4be21dacee49395013caae28576484a049a4f
- git.kernel.org/stable/c/6776efe4a52f289a3fc18f8adf19b035a7d8e1bb
- nvd.nist.gov/vuln/detail/CVE-2026-89565
- github.com/advisories/GHSA-x2xj-xv7g-fj5c
- git.kernel.org/stable/c/c4dc23de4cc75e4e304170b31bb8aeeacd5cb990
- git.kernel.org/stable/c/6d8c5b266d0035a061573843a7243be068eb6118
- git.kernel.org/stable/c/fd01f1a3ed4a189a784654f7c69eb565872f2e12
Elsewhere on this site
Related CVEs (same products)
- Unknown CVE-2026-99086 dm-integrity: validate the superblock on resume 7h
- Unknown CVE-2026-99087 dm-integrity: fix NULL pointer dereference when the 'R' flag is used 7h
- Unknown CVE-2026-99079 net/mlx5e: Prevent stale XSK buffer release on refill retry 7h
- Unknown CVE-2026-99080 fs: Free any excess xarray nodes in clear_inode() 7h
- Unknown CVE-2026-99081 bnxt_en: fix DMA mapping length for padded small packets 7h
- Unknown CVE-2026-99082 KVM: x86: Use active memslots for the per-vCPU MMIO cache 7h
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-2026-89565 is "ipip: fix skb leak in collect_md mode when metadata_dst allocation fails", 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 0.17% 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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