CVE-2025-21905

Kernel memory disclosure via unterminated firmware TLV

Published Apr 1, 2025 · Updated May 11, 2026

Out-of-bounds read in the Linux kernel iwlwifi driver allows local users to expose adjacent memory through a crafted firmware TLV. The iwl_parse_tlv_firmware function passes the fixed-size FSEQ version field to an unbounded %s log conversion even when the TLV lacks a NUL terminator. Triggering the read requires root or CAP_SYS_ADMIN access to replace a file under /lib/firmware; the log discloses adjacent memory and, for a final TLV, reads beyond the firmware file buffer.

CVSS severity7.1
High
EPSS probability0.24%
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

Out-of-bounds read in the Linux kernel iwlwifi driver allows local users to expose adjacent memory through a crafted firmware TLV. The iwl_parse_tlv_firmware function passes the fixed-size FSEQ version field to an unbounded %s log conversion even when the TLV lacks a NUL terminator. Triggering the read requires root or CAP_SYS_ADMIN access to replace a file under /lib/firmware; the log discloses adjacent memory and, for a final TLV, reads beyond the firmware file buffer.

The record

CVE
CVE-2025-21905
Published
Apr 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1005
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Apr 1, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record 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=5.2
  2. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <38f0d398b6d7640d223db69df022c4a232f24774
  3. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <47616b82f2d42ea2060334746fed9a2988d845c9
  4. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <59cdda202829d1d6a095d233386870a59aff986f
  5. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <88ed69f924638c7503644e1f8eed1e976f3ffa7a
  6. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <b02f8d5a71c8571ccf77f285737c566db73ef5e5
  7. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <c0e626f2b2390472afac52dfe72b29daf9ed8e1d
  8. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <e0dc2c1bef722cbf16ae557690861e5f91208129
  9. Affected versionversion=aee1b6385e29e472ae5592b9652b750a29bf702e <f265e6031d0bc4fc40c4619cb42466722b46eaa9

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=5.2; version=aee1b6385e29e472ae5592b9652b750a29bf702e <38f0d398b6d7640d223db69df022c4a232f24774; version=aee1b6385e29e472ae5592b9652b750a29bf702e <47616b82f2d42ea2060334746fed9a2988d845c9; version=aee1b6385e29e472ae5592b9652b750a29bf702e <59cdda202829d1d6a095d233386870a59aff986f; version=aee1b6385e29e472ae5592b9652b750a29bf702e <88ed69f924638c7503644e1f8eed1e976f3ffa7a; version=aee1b6385e29e472ae5592b9652b750a29bf702e <b02f8d5a71c8571ccf77f285737c566db73ef5e5; version=aee1b6385e29e472ae5592b9652b750a29bf702e <c0e626f2b2390472afac52dfe72b29daf9ed8e1d; version=aee1b6385e29e472ae5592b9652b750a29bf702e <e0dc2c1bef722cbf16ae557690861e5f91208129; version=aee1b6385e29e472ae5592b9652b750a29bf702e <f265e6031d0bc4fc40c4619cb42466722b46eaa9

Published CVSS scores

7.1UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
6.0OracleCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

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