VulnerabilityPublished 18 Oct 2026

CVE-2026-98547: Linux kernel · af_packet: fix integer overflow in prb_calc_retire_blk_tmo()

Source GCVE Database

Authoritative record:CVE-2026-98547· High

Not known to be exploited · fixed in eb5b3838b9200dac04bfe33483db0ee8287456fb : patch Linux kernel soon.

Data as of 26 Oct 2026, 12:55 UTC

Severity

High

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.2% chance of exploitation in 30 days – higher than 11% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in eb5b3838b9200dac04bfe33483db0ee8287456fb, be1aacff399d519cc48d6b34354a54dd79041140, b2bcc6a254d6f27823a56787668ae4ee8cdb6e71 +5

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-9w5q-r82v-2r6x

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < eb5b3838b9200dac04bfe33483db0ee8287456fb	Fixed in eb5b3838b9200dac04bfe33483db0ee8287456fb
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < be1aacff399d519cc48d6b34354a54dd79041140	Fixed in be1aacff399d519cc48d6b34354a54dd79041140
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < b2bcc6a254d6f27823a56787668ae4ee8cdb6e71	Fixed in b2bcc6a254d6f27823a56787668ae4ee8cdb6e71
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < 6279211e7d2456ecd195d236c9ee5e5c6fa5a17a	Fixed in 6279211e7d2456ecd195d236c9ee5e5c6fa5a17a
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < 297acc571d5813db76b147c745b91031d5f9c960	Fixed in 297acc571d5813db76b147c745b91031d5f9c960
LinuxLinux	Affected ≥ f6fb8f100b807378fda19e83e5ac6828b638603a, < 218a944b9e035d4b47d59c69af6ca13319da15fb	Fixed in 218a944b9e035d4b47d59c69af6ca13319da15fb

AI-suggested

A fix is available that changes the arithmetic in prb_calc_retire_blk_tmo() from 32-bit to 64-bit to prevent integer overflow. Users should update their Linux kernel to a version that includes this fix. No other mitigations are indicated or required according to the advisory.

Description

A vulnerability in the Linux kernel's af_packet subsystem involves an integer overflow in the prb_calc_retire_blk_tmo() function. This overflow can cause a negative timeout value to be used in a high-resolution timer, resulting in a timer that fires continuously at maximum rate. This behavior can cause a CPU to spin indefinitely in a softirq context, effectively leading to a denial of service. The issue arises from 32-bit integer arithmetic overflow when calculating block size timeouts, triggered by user-controlled parameters. The vulnerability has been resolved by changing the calculation to use 64-bit arithmetic.

Impact

The vulnerability can cause a denial of service by making a CPU core spin indefinitely in a softirq context, holding a kernel lock and effectively hanging the system or degrading performance severely. This occurs when a specially crafted packet ring buffer configuration is used with a large block size, triggering the integer overflow and continuous timer firing. There is no indication of privilege escalation or data corruption from the provided information.

References

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