vulnerability / NVI-00005747 / Revision 2
PhpSpreadsheet has XSS via NumberFormat @ Text Substitution in HTML Writer
OSV carries this publisher advisory for phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet, phpoffice/phpspreadsheet. This is an aggregated source copy; consult the original publisher and compare update dates.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
5.4 MEDIUM (3.1)
nvd@nist.gov severity; no combined Null risk score.
4.8 MEDIUM (4.0)
security-advisories@github.com severity; no combined Null risk score.
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 4.0.0; fixed 5.7.0
### Summary The HTML Writer in PhpSpreadsheet bypasses `htmlspecialchars()` output escaping when a cell uses a custom number format containing the `@` text placeholder with additional literal text (e.g., `@ "items"` or `"Total: "@`). This allows an attacker to inject arbitrary HTML and JavaScript into the generated HTML output by crafting a malicious XLSX file. ### Details #### 1. Conditional escaping in `Html.php:1586-1594` ```php $cellData = NumberFormat::toFormattedString( $origData2, $formatCode ?? NumberFormat::FORMAT_GENERAL, [$this, 'formatColor'] ); if ($cellData === $origData) { $cellData = htmlspecialchars($cellData, Settings::htmlEntityFlags()); } ``` `htmlspecialchars()` is only called when `$cellData === $origData` (strict comparison). If the formatted output differs from the original value in any way, escaping is skipped entirely. #### 2. Early return in `Formatter.php:136-152` ```php if (preg_match(self::SECTION_SPLIT, $format) === 0 && preg_match(self::SYMBOL_AT, $formatx) === 1) { if (!str_contains($format, '"')) { return str_replace('@', /* raw value */, $format); } return str_replace(/* ... preg_replace with raw val
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 3.3.0; fixed 3.10.5
### Summary The HTML Writer in PhpSpreadsheet bypasses `htmlspecialchars()` output escaping when a cell uses a custom number format containing the `@` text placeholder with additional literal text (e.g., `@ "items"` or `"Total: "@`). This allows an attacker to inject arbitrary HTML and JavaScript into the generated HTML output by crafting a malicious XLSX file. ### Details #### 1. Conditional escaping in `Html.php:1586-1594` ```php $cellData = NumberFormat::toFormattedString( $origData2, $formatCode ?? NumberFormat::FORMAT_GENERAL, [$this, 'formatColor'] ); if ($cellData === $origData) { $cellData = htmlspecialchars($cellData, Settings::htmlEntityFlags()); } ``` `htmlspecialchars()` is only called when `$cellData === $origData` (strict comparison). If the formatted output differs from the original value in any way, escaping is skipped entirely. #### 2. Early return in `Formatter.php:136-152` ```php if (preg_match(self::SECTION_SPLIT, $format) === 0 && preg_match(self::SYMBOL_AT, $formatx) === 1) { if (!str_contains($format, '"')) { return str_replace('@', /* raw value */, $format); } return str_replace(/* ... preg_replace with raw val
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 2.2.0; fixed 2.4.5
### Summary The HTML Writer in PhpSpreadsheet bypasses `htmlspecialchars()` output escaping when a cell uses a custom number format containing the `@` text placeholder with additional literal text (e.g., `@ "items"` or `"Total: "@`). This allows an attacker to inject arbitrary HTML and JavaScript into the generated HTML output by crafting a malicious XLSX file. ### Details #### 1. Conditional escaping in `Html.php:1586-1594` ```php $cellData = NumberFormat::toFormattedString( $origData2, $formatCode ?? NumberFormat::FORMAT_GENERAL, [$this, 'formatColor'] ); if ($cellData === $origData) { $cellData = htmlspecialchars($cellData, Settings::htmlEntityFlags()); } ``` `htmlspecialchars()` is only called when `$cellData === $origData` (strict comparison). If the formatted output differs from the original value in any way, escaping is skipped entirely. #### 2. Early return in `Formatter.php:136-152` ```php if (preg_match(self::SECTION_SPLIT, $format) === 0 && preg_match(self::SYMBOL_AT, $formatx) === 1) { if (!str_contains($format, '"')) { return str_replace('@', /* raw value */, $format); } return str_replace(/* ... preg_replace with raw val
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 2.0.0; fixed 2.1.16
### Summary The HTML Writer in PhpSpreadsheet bypasses `htmlspecialchars()` output escaping when a cell uses a custom number format containing the `@` text placeholder with additional literal text (e.g., `@ "items"` or `"Total: "@`). This allows an attacker to inject arbitrary HTML and JavaScript into the generated HTML output by crafting a malicious XLSX file. ### Details #### 1. Conditional escaping in `Html.php:1586-1594` ```php $cellData = NumberFormat::toFormattedString( $origData2, $formatCode ?? NumberFormat::FORMAT_GENERAL, [$this, 'formatColor'] ); if ($cellData === $origData) { $cellData = htmlspecialchars($cellData, Settings::htmlEntityFlags()); } ``` `htmlspecialchars()` is only called when `$cellData === $origData` (strict comparison). If the formatted output differs from the original value in any way, escaping is skipped entirely. #### 2. Early return in `Formatter.php:136-152` ```php if (preg_match(self::SECTION_SPLIT, $format) === 0 && preg_match(self::SYMBOL_AT, $formatx) === 1) { if (!str_contains($format, '"')) { return str_replace('@', /* raw value */, $format); } return str_replace(/* ... preg_replace with raw val
phpoffice/phpspreadsheet
source listedECOSYSTEM: introduced 0; fixed 1.30.4
### Summary The HTML Writer in PhpSpreadsheet bypasses `htmlspecialchars()` output escaping when a cell uses a custom number format containing the `@` text placeholder with additional literal text (e.g., `@ "items"` or `"Total: "@`). This allows an attacker to inject arbitrary HTML and JavaScript into the generated HTML output by crafting a malicious XLSX file. ### Details #### 1. Conditional escaping in `Html.php:1586-1594` ```php $cellData = NumberFormat::toFormattedString( $origData2, $formatCode ?? NumberFormat::FORMAT_GENERAL, [$this, 'formatColor'] ); if ($cellData === $origData) { $cellData = htmlspecialchars($cellData, Settings::htmlEntityFlags()); } ``` `htmlspecialchars()` is only called when `$cellData === $origData` (strict comparison). If the formatted output differs from the original value in any way, escaping is skipped entirely. #### 2. Early return in `Formatter.php:136-152` ```php if (preg_match(self::SECTION_SPLIT, $format) === 0 && preg_match(self::SYMBOL_AT, $formatx) === 1) { if (!str_contains($format, '"')) { return str_replace('@', /* raw value */, $format); } return str_replace(/* ... preg_replace with raw val
03 / Response
What to do next
- vendor patch
The original advisory lists fixed boundaries 5.7.0 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 3.10.5 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 2.4.5 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 2.1.16 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- vendor patch
The original advisory lists fixed boundaries 1.30.4 for phpoffice/phpspreadsheet. Confirm the publisher’s latest guidance.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. NIST National Vulnerability Database
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- GHSA-6wpp-88cp-7q68 ↗
GitHub Advisory Database via OSV · vendor advisory
Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.
- CVE-2026-35453 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 2 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.