CVE-2026-125756: postalsys postal-mime · Interpretation Conflict
Affects postalsys postal-mimeSource CVE Database V5
Not known to be exploited · CVSS 8.2 High : upgrade to 4.2.1 soon.
Data as of 10 Nov 2026, 15:34 UTC
Thin evidence
One scorer or none| CNA (VulnCheck) | CVSS 4.0 | 8.2 |
|---|---|---|
| CNA (VulnCheck) | CVSS 3.1 | 5.9 |
- Patch
- Available – fixed in 4.2.1
CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade postalsys postal-mime to 4.2.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| postalsyspostal-mime | Affected
| Fixed in
|
npmpostal-mimepkg:npm/postal-mimeOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade postal-mime to version 4.2.1 or later, where this vulnerability is fixed. No other mitigation is indicated by the vendor advisory.
Description
postal-mime versions before 4.2.1 have a parser vulnerability in the address parser that truncates the domain at folding whitespace or comments before a dot. This allows remote attackers to craft From headers that can pass SPF, DKIM, and DMARC alignment checks for their own subdomain while the parser reports a spoofed victim sender address.
References
- github.com/postalsys/postal-mime/security/advisories/GHSA-jh3p-792r-98gm (opens in a new tab)
- github.com/postalsys/postal-mime/commit/646725704463839f233472453b7c8306bd1dde21 (opens in a new tab)
- github.com/postalsys/postal-mime/releases/tag/v4.2.1 (opens in a new tab)
- github.com/postalsys/postal-mime/blob/939a220bd518f54d98a088c315d7227e6215cae3/src/address-parser.ts (opens in a new tab)
- vulncheck.com/advisories/postal-mime-before-4.2.1-sender-spoofing-via-address-parser-domain-truncation (opens in a new tab)