VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98857: Linux kernel · ipvs: bound LBLCR and LBLC cache growth

Source GCVE Database

Authoritative record:CVE-2026-98857

Not known to be exploited · fixed in bc9ff8e64771cc32a216953fe615386f46ac1eaa : update Linux kernel when convenient.

Data as of 26 Oct 2026, 13:47 UTC

Severity

Medium

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 4% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in bc9ff8e64771cc32a216953fe615386f46ac1eaa, 31028d7b970962fbeda1e9131405c76551094300, 6316d17324bd4ca400c26adb7b656c6e3447c209 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-3qgh-gjj6-qj8r

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < bc9ff8e64771cc32a216953fe615386f46ac1eaa	Fixed in bc9ff8e64771cc32a216953fe615386f46ac1eaa
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 31028d7b970962fbeda1e9131405c76551094300	Fixed in 31028d7b970962fbeda1e9131405c76551094300
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 6316d17324bd4ca400c26adb7b656c6e3447c209	Fixed in 6316d17324bd4ca400c26adb7b656c6e3447c209
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 16c83c047ecfaf226ad81d45d77fa11a3184d0e4	Fixed in 16c83c047ecfaf226ad81d45d77fa11a3184d0e4
LinuxLinux	Affected ≥ 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2, < 2a3c3de660f96865f303fd25f1285f2ffbfd521d	Fixed in 2a3c3de660f96865f303fd25f1285f2ffbfd521d
LinuxLinux	Affected =2.6.12	Fixed in–

AI-suggested

A fix has been implemented in the Linux kernel to bound the growth of the LBLCR and LBLC caches by rejecting new entries once the cache size reaches 1.5 times the configured max_size. Users should apply the official Linux kernel update that includes this patch to remediate the vulnerability. No additional mitigation steps are indicated.

Description

A vulnerability in the Linux kernel's IP Virtual Server (IPVS) component related to unbounded growth of LBLCR and LBLC cache entries has been resolved. The functions ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for every new destination address without effectively limiting the cache size, allowing potential resource exhaustion. The fix introduces a limit to reject new cache entries once the cache size reaches 1.5 times the configured max_size, preventing uncontrolled growth while maintaining service availability.

Impact

The vulnerability could allow an attacker to cause unbounded growth of IPVS cache tables, potentially leading to resource exhaustion and degraded service availability. However, the fix ensures that new cache entries are rejected beyond a threshold, maintaining serviceability and preventing further cache growth.

Summary

The Linux kernel IPVS component had a vulnerability where the LBLCR and LBLC caches could grow without effective bounds because the max_size parameter only triggered periodic reclamation after the cache exceeded the limit, but did not prevent attackers from continuously adding new entries. This could lead to resource exhaustion. The patch bounds cache growth by rejecting new entries once the cache size reaches max_size * 3 / 2, allowing the periodic collector to reclaim entries and the scheduler fallback to continue serving traffic without further cache growth.

References

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