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NVD / CVE Program· CNA Linux

CVE-2026-80848: xfrm: espintcp: fix UAF during close

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: 0.19% (FIRST EPSS).
  • Fixed version: Linux Linux 24efebecf415ba264adba0f0491cec436463a14f, 29121c5e6591da527e8e36ddac7120dc527f574d, 4b31a875693c480c611519faca46216514e3e052.

Low priority for now. Upgrade to Linux Linux 24efebecf415ba264adba0f0491cec436463a14f, 29121c5e6591da527e8e36ddac7120dc527f574d, 4b31a875693c480c611519faca46216514e3e052 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: xfrm: espintcp: fix UAF during close ZDI reported and analyzed a race condition during close for espintcp sockets: espintcp_close() frees emsg->skb via kfree_skb() without holding any socket lock. Concurrently, the xfrm_trans_reinject work queue invokes esp_output_tcp_finish() -> espintcp_push_skb() -> espintcp_push_msgs() -> skb_send_sock_locked(), which reads the same skb as a data source. Fix this by adding a synchronize_rcu() call after resetting sk_prot, since esp_output_tcp_finish() runs under RCU and won't use a socket with sk_prot == &tcp_prot. Simply taking the socket lock in espintcp_close() could lead to leaks, if esp_output_tcp_finish() re-adds an skb in the slot we just freed. After this, the existing barrier() is no longer needed.

—No exploit Fix available
Published
Sep 4, 2026
Updated
Oct 19, 2026
EPSS
0.1% · 9th 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 · 0.1%

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  • No public exploit code on record
  • A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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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

    • 5.6affected
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 29121c5e6591da527e8e36ddac7120dc527f574daffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before ed5d9102190c45fc70121c036b0626b740040b75affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 4bc0dfa28dca6fc0084203732695968049c44072affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before ff8dd7a932f34409a56e1b91a1219340f17457e9affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 4b31a875693c480c611519faca46216514e3e052affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 24efebecf415ba264adba0f0491cec436463a14faffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before eb3bbf29c723fe75c0eb92be14f0ec92971fe272affected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before 54b41ad14da9a981131ab6e4d3f79321a503ea5daffected · git
    • e27cca96cd68fa2c6814c90f9a1cfd36bb68c593 and later · before deb232e884877bf10b4ce2580909eedec986c284affected · git

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.187-16.1.187-1
Debian:12linux-6.12before 6.12.111-1~deb12u16.12.111-1~deb12u1
Debian:13linuxbefore 6.12.111-16.12.111-1
Debian:14linuxbefore 7.1.13-17.1.13-1

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-2026-80846Sep 4, 2026 · xfrm: drop ESP-in-TCP packets with no ingress device
    0Monitor
  • ← EarlierCVE-2026-80847Sep 4, 2026 · tcp: clamp route advmss to TCP_MIN_MSS
    0Monitor
  • Later →CVE-2026-80849Sep 4, 2026 · net/tcp-ao: fix use-after-free of current_key on reconnect to another peer
    0Monitor

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 Linux24efebecf415ba264adba0f0491cec436463a14fVendor (CNA)
Linux Linux29121c5e6591da527e8e36ddac7120dc527f574dVendor (CNA)
Linux Linux4b31a875693c480c611519faca46216514e3e052Vendor (CNA)
Linux Linux4bc0dfa28dca6fc0084203732695968049c44072Vendor (CNA)
Linux Linux54b41ad14da9a981131ab6e4d3f79321a503ea5dVendor (CNA)
Linux Linuxdeb232e884877bf10b4ce2580909eedec986c284Vendor (CNA)
Linux Linuxeb3bbf29c723fe75c0eb92be14f0ec92971fe272Vendor (CNA)
Linux Linuxed5d9102190c45fc70121c036b0626b740040b75Vendor (CNA)
Linux Linuxff8dd7a932f34409a56e1b91a1219340f17457e9Vendor (CNA)
azl3 kernel 6.6.150.1-1 on Azure Linux 3.0—Microsoft (MSRC)
debian:linux6.1.187-1 · Debian:12Package 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).

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 (8 more)

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

All records