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[GHSA-qv9r-c865-cp47] Improper encoding of non-finite floating-point values... #8693

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[GHSA-qv9r-c865-cp47] Improper encoding of non-finite floating-point values... #8693

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74 changes: 70 additions & 4 deletions advisories/unreviewed/2026/07/GHSA-qv9r-c865-cp47/GHSA-qv9r-c865-cp47.json
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Original file line number Diff line number Diff line change
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{
"schema_version": "1.4.0",
"id": "GHSA-qv9r-c865-cp47",
"modified": "2026-07-11T00:31:48Z",
"modified": "2026-07-11T00:31:56Z",
"published": "2026-07-11T00:31:48Z",
"aliases": [
"CVE-2026-49844"
],
"details": "Improper encoding of non-finite floating-point values during MapMessage JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0.\n\nThe fix for CVE-2026-34481 did not cover all code paths: when a MapMessage contains a non-finite IEEE 754 value (NaN, Infinity, or -Infinity), MapMessage.asJson() emits the corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the resulting document.\n\nThe defect is reachable only when both of the following conditions hold:\n\n * The application uses the message resolver https://logging.apache.org/log4j/2.x/manual/json-template-layout.html#event-template-resolver-message of JsonTemplateLayout or any other layout that relies on MapMessage.asJson() or MapMessage.getFormattedMessage(new String[]{\"JSON\"}).\n * The application logs a MapMessage that contains an attacker-controlled floating-point value.\n\n\nAn attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or disrupt downstream log ingestion and parsing.\n\nUsers are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values.",
"summary": "Apache Log4j API: Improper serialization of non-finite floating-point values in `MapMessage.asJson()`",
"details": "Improper encoding of non-finite floating-point values during `MapMessage` JSON serialization in Apache Log4j API produces output that is not valid JSON. This issue affects Apache Log4j API versions 2.13.1 through 2.25.4 and version 2.26.0.\n\nThe fix for CVE-2026-34481 did not cover all code paths: when a `MapMessage` contains a non-finite IEEE 754 value (`NaN`, `Infinity`, or `-Infinity`), `MapMessage.asJson()` emits the corresponding bare token. RFC 8259 does not permit these tokens, so a conformant parser rejects the resulting document.\n\nThe defect is reachable only when both of the following conditions hold:\n\n * The application uses the [`message` resolver](https://logging.apache.org/log4j/2.x/manual/json-template-layout.html#event-template-resolver-message) of `JsonTemplateLayout` or any other layout that relies on `MapMessage.asJson()` or `MapMessage.getFormattedMessage(new String[]{\"JSON\"})`.\n * The application logs a `MapMessage` that contains an attacker-controlled floating-point value.\n\n\nAn attacker who can supply a non-finite value can cause the affected layout to emit malformed JSON, which may corrupt the enclosing log record or disrupt downstream log ingestion and parsing.\n\nUsers are advised to upgrade to Apache Log4j API 2.25.5 or 2.26.1, both of which emit RFC 8259-compliant JSON for non-finite values.",

@ppkarwasz ppkarwasz Jul 13, 2026

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I don't think it is worth cluttering the description with pre-release versions. Alpha and beta versions of Log4j are not meant to be used in production.

"severity": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N"
}
],
"affected": [
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.logging.log4j:log4j-api"
},
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "2.13.1"
},
{
"fixed": "2.25.5"
}
]
}
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.logging.log4j:log4j-api"
},
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "2.26.0"
},
{
"fixed": "2.26.1"
}
]
}
],
"versions": [
"2.26.0"
]
},
{
"package": {
"ecosystem": "Maven",
"name": "org.apache.logging.log4j:log4j-api"
},
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "3.0.0-alpha1"
},
{
"last_affected": "3.0.0-beta2"
}
]
}
]
}
],
"affected": [],
"references": [
{
"type": "ADVISORY",
Expand All @@ -23,6 +85,10 @@
"type": "WEB",
"url": "https://github.com/apache/logging-log4j2/pull/4163"
},
{
"type": "WEB",

@ppkarwasz ppkarwasz Jul 13, 2026

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This is what the UI chose to insert.

"url": "https://github.com/apache/logging-log4j2"
},
{
"type": "WEB",
"url": "https://logging.apache.org/cyclonedx/vdr.xml"
Expand Down