CVE Intelligence
Medium Denial of service

CVE-2025-38614 — eventpoll: Fix semi-unbounded recursion

In the Linux kernel, the following vulnerability has been resolved: eventpoll: Fix semi-unbounded recursion Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges.

Published Aug 19, 2025 · Updated Oct 15, 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)+1
  • Technical severity (medium)+3

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
0.18%
ahead of 7% of scored CVEs · Oct 15, 2026
Affects
Debian
Debian Linux and 2 more
CVSS base
5.5
Medium · 4 source(s)
Prioritization reference: 7.8 provisional

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

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

  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)
  • Documented patch — git.kernel.org (NIST National Vulnerability Database)

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 (Debian Debian Linux, Linux Linux, Linux Linux Kernel).
  2. Apply the fixed version or the patch documented under Remediation.
  3. Search available logs for exploit probes matching the vulnerability class (denial of service), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Debian Debian Linux version 11.0 Vulnerable NIST National Vulnerability Database
Linux Linux version 0eccd188cfeaf857a26f2d72941d27d298cf6a54≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < 7a2125962c42d5336ca0495a9ce4cb38a63e9161≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < ea5f97dbdcb1651581a22bd10afd2f0dd9dc11d6≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < 3542c90797bc3ab83ebab54b737d751cf3682036≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < f2e467a48287c868818085aa35389a224d226732version 8216e1a0d47cae06a75c42346f19dffe14e42d57version 28a92748aa4bc57d35e7b079498b0ac2e7610a37version 7eebcd4792c5a341559aed327b6afecbb1c46402
and 10 more ≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < 1b13b033062824495554e836a1ff5f85ccf6b039version a72affdbb09f3f24f64ffcbbdf62c2e57c58f379≥ 2.6.32.30 and < 2.6.33≥ 2.6.33.8 and < 2.6.34≥ 2.6.34.10 and < 2.6.35≥ 2.6.35.12 and < 2.6.36≥ 2.6.37.3 and < 2.6.38version 2.6.38≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < 2a0c0c974bea9619c6f41794775ae4b97530e0e6≥ 22bacca48a1755f79b7e0f192ddb9fbb7fc6e64e and < 71379495ab70eaba19224bd71b5b9b399eb85e04
Vulnerable CVE Program (cve.org) e CISA ADP
Linux Linux Kernel version 2.6.38-rc8version 2.6.38-rc7version 2.6.38≥ 6.16 and < 6.16.1≥ 6.13 and < 6.15.11≥ 6.7 and < 6.12.43≥ 6.2 and < 6.6.103≥ 5.16 and < 6.1.149
and 6 more ≥ 2.6.38.1 and < 5.15.190≥ 2.6.37.3 and < 2.6.38≥ 2.6.35.12 and < 2.6.36≥ 2.6.34.10 and < 2.6.35≥ 2.6.33.8 and < 2.6.34≥ 2.6.32.30 and < 2.6.33
Vulnerable NIST National Vulnerability Database

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
7.8 CVSS 3.1 High 1.8 5.9 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database
7.8 CVSS 3.1 High — — Linux via CVE Program (cve.org) e CISA ADP
5.5 CVSS 3.1 Medium 1.8 3.6 nvd@nist.gov via NIST National Vulnerability Database
5.5 CVSS 3.1 Medium — — GitHub, Inc. via GitHub Security Advisories
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H (score shown at the top: nvd@nist.gov)
Scoring entities (NIST, CNA, ADP) score independently; each score is shown with its origin. For prioritization we use 7.8 (416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database) as a conservative provisional reference — not a definitive official score.

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-674 · Uncontrolled Recursion

Other CVEs with this weakness →

EPSS over time FIRST

Oct 14, 2026 → Oct 15, 2026 · 2 reading(s) · max 0.18%

Detection

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

  • Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
  • Track CPU/memory spikes and availability drops correlated with request patterns.
endpoint telemetry (EDR)resource metrics

Timeline

What happened to this CVE, newest first.

  • 2026
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Affected products added · linux/linux
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • Fix documented
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVSS changed · 5.5
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Modified
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • 2025
  • CVE published
    Aug 19, 2025 · Linux

Source activity

Repeated readings are counted rather than listed.

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

References

14 on the record

Elsewhere on this site

Debian
every CVE for this vendor
Denial of service
same class
CWE-674
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-99999 ipv4: validate checksum_start before completing checksum 12h
  • CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 12h
  • CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
  • CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
  • CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
  • CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d

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 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-2025-38614 is "eventpoll: Fix semi-unbounded recursion", rated Medium. It affects Debian Linux (Debian); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.5 describes technical severity. EPSS 0.18% 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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