CVE-2022-26485Known exploitationNetwork attack vector

Code execution via XSLT parameter use-after-free

Published Dec 22, 2022 · Updated Oct 21, 2025

Use-after-free in Mozilla Firefox-family products and Thunderbird allows remote attackers to execute code through crafted XSLT content. Removing an XSLT parameter during processing leaves txVariable::Convert using freed heap memory. Exploitation requires a user to process attacker-controlled content and grants code execution in the application's context.

CVSS severity8.8
High
EPSS probability14.26%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Mozilla Firefox-family products and Thunderbird allows remote attackers to execute code through crafted XSLT content. Removing an XSLT parameter during processing leaves txVariable::Convert using freed heap memory. Exploitation requires a user to process attacker-controlled content and grants code execution in the application's context.

The record

CVE
CVE-2022-26485
Published
Dec 22, 2022
Updated
Oct 21, 2025
Vendor
Mozilla
Product
Firefox
Classifications
CWE-416, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 7, 2022Exploitation reportedCISA Known Exploited Vulnerabilities listing
  2. Dec 22, 2022CVE publishedPublication date reported by the CVE source.
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <97.0.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Mozilla · Firefoxversion=unspecified <97.0.2
Mozilla · Firefox Focusversion=unspecified <97.3.0
Mozilla · Thunderbirdversion=unspecified <91.6.2
Mozilla · Firefox for Androidversion=unspecified <97.3.0
Mozilla · Firefox ESRversion=unspecified <91.6.1

Published CVSS scores

8.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free
T1203Exploitation for Client Execution

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.

Reported exploitation

Technologies

Your stack

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Your stack

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