Mattermost versions 11.10.x <= 11.10.0, 11.7.x <= 11.7.9, 11.9.x <= 11.9.1, 11.8.x <= 11.8.5 fail to limit the size of remote image responses buffered in memory during local image proxy direct fetches, which allows a remote attacker to cause memory exhaustion on the server via a crafted oversized image response.. Mattermost Advisory ID: MMSA-2026-00726
{
"cna_assigner": "Mattermost",
"cwe_ids": [
"CWE-770"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/16xxx/CVE-2026-16251.json",
"unresolved_ranges": [
{
"extracted_events": [
{
"range": [
{
"introduced": "11.10.0"
},
{
"last_affected": "11.10.0"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandaloneSingleVersion"
}
]
},
{
"extracted_events": [
{
"range": [
{
"introduced": "11.7.0"
},
{
"last_affected": "11.7.9"
},
{
"introduced": "11.9.0"
},
{
"last_affected": "11.9.1"
},
{
"introduced": "11.8.0"
},
{
"last_affected": "11.8.5"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
]
}{
"extracted_events": [
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "11.7.0"
},
{
"fixed": "11.7.10"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "11.9.0"
},
{
"fixed": "11.9.2"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:mattermost:mattermost_server:11.10.0:*:*:*:*:*:*:*",
"range": [
{
"introduced": "11.10.0"
},
{
"last_affected": "11.10.0"
}
],
"source": "CPE_STRING"
}
]
}