CVE-2023-53373

Local privilege escalation via backlogged seqiv request

Published Sep 18, 2025 · Updated Sep 18, 2025

Use-after-free in Linux kernel seqiv allows local users to corrupt kernel memory through backlogged AF_ALG encryption requests. The seqiv completion path treats -EBUSY as an ordinary failure and frees the temporary IV even though the queued request still references it. An unprivileged local account can drive concurrent AF_ALG AEAD operations to the backlog, leading to kernel disclosure, privilege escalation, or a panic.

CVSS severity7.8
High
EPSS probability0.16%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Use-after-free in Linux kernel seqiv allows local users to corrupt kernel memory through backlogged AF_ALG encryption requests. The seqiv completion path treats -EBUSY as an ordinary failure and frees the temporary IV even though the queued request still references it. An unprivileged local account can drive concurrent AF_ALG AEAD operations to the backlog, leading to kernel disclosure, privilege escalation, or a panic.

The record

CVE
CVE-2023-53373
Published
Sep 18, 2025
Updated
Sep 18, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-416, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 18, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <1effbddaff60eeef8017c6dea1ee0ed970164d14
  2. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <32e62025e5e52fbe4812ef044759de7010b15dbc
  3. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <36ec108b7bd7e280edb22de028467bd09d644620
  4. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <4d497e8b200a175094e0ac252ed878add39b8771
  5. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <63551e4b7cbcd9914258827699eb2cb6ed6e4a16
  6. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <9477db935eb690f697d9bcc4f608927841bc8b36
  7. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <ae849d2f48019ff9c104e32bf588ccbfb200e971
  8. Affected versionversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <cc4d0d4251748a8a68026938f4055d2ac47c5719
  9. Affected versionversion=2.6.25

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <1effbddaff60eeef8017c6dea1ee0ed970164d14; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <32e62025e5e52fbe4812ef044759de7010b15dbc; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <36ec108b7bd7e280edb22de028467bd09d644620; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <4d497e8b200a175094e0ac252ed878add39b8771; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <63551e4b7cbcd9914258827699eb2cb6ed6e4a16; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <9477db935eb690f697d9bcc4f608927841bc8b36; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <ae849d2f48019ff9c104e32bf588ccbfb200e971; version=0a270321dbf948963aeb0e8382fe17d2c2eb3771 <cc4d0d4251748a8a68026938f4055d2ac47c5719; version=2.6.25

Published CVSS scores

7.8CISA ADPCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1OracleCVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo