FKIE_CVE-2026-74987

Vulnerability from fkie_nvd - Published: 2026-08-18 13:17 - Updated: 2026-08-18 19:17
Severity
Summary
Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1.
References
security@mozilla.orghttps://bugzilla.mozilla.org/buglist.cgi?bug_id=1500946%2C1788109%2C2045379%2C2045380%2C2049339%2C2049393%2C2053580%2C2054662%2C2054665%2C2054673%2C2054785%2C2058645
security@mozilla.orghttps://bugzilla.mozilla.org/buglist.cgi?bug_id=2048797%2C2050536%2C2053272%2C2053579%2C2057115%2C2057116%2C2057130%2C2057991%2C2057995%2C2058002%2C2058008%2C2058032%2C2058102%2C2058667
security@mozilla.orghttps://bugzilla.mozilla.org/show_bug.cgi?id=2059424
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-74/
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-76/
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-77/
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-78/
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-79/
security@mozilla.orghttps://www.mozilla.org/security/advisories/mfsa2026-80/
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Firefox",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "140.*",
              "status": "unaffected",
              "version": "140.14",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "153.*",
              "status": "unaffected",
              "version": "153.1",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "154",
              "versionType": "rpm"
            }
          ]
        },
        {
          "product": "Thunderbird",
          "vendor": "Mozilla",
          "versions": [
            {
              "lessThanOrEqual": "140.*",
              "status": "unaffected",
              "version": "140.14",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "153.*",
              "status": "unaffected",
              "version": "153.1",
              "versionType": "rpm"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "154",
              "versionType": "rpm"
            }
          ]
        }
      ],
      "source": "security@mozilla.org"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Internally found bugs present in Thunderbird ESR 140.13, Thunderbird ESR 153.0 and Thunderbird 153. Some of these bugs showed evidence of memory corruption or another security-relevant defect and we presume that with enough effort some of these could have been exploited. This vulnerability was fixed in Firefox 154, Firefox ESR 140.14, Firefox ESR 153.1, Thunderbird 154, Thunderbird 140.14, and Thunderbird 153.1."
    }
  ],
  "id": "CVE-2026-74987",
  "lastModified": "2026-08-18T19:17:17.087",
  "metrics": {},
  "published": "2026-08-18T13:17:40.560",
  "references": [
    {
      "source": "security@mozilla.org",
      "url": "https://bugzilla.mozilla.org/buglist.cgi?bug_id=1500946%2C1788109%2C2045379%2C2045380%2C2049339%2C2049393%2C2053580%2C2054662%2C2054665%2C2054673%2C2054785%2C2058645"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://bugzilla.mozilla.org/buglist.cgi?bug_id=2048797%2C2050536%2C2053272%2C2053579%2C2057115%2C2057116%2C2057130%2C2057991%2C2057995%2C2058002%2C2058008%2C2058032%2C2058102%2C2058667"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2059424"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-74/"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-76/"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-77/"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-78/"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-79/"
    },
    {
      "source": "security@mozilla.org",
      "url": "https://www.mozilla.org/security/advisories/mfsa2026-80/"
    }
  ],
  "sourceIdentifier": "security@mozilla.org",
  "vulnStatus": "Undergoing Analysis"
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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