CVE-2026-91995: pig before 4.1.0 Unverified Password Change via /register/password
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-08 00:03 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
pig before 4.1.0 contains an authentication bypass vulnerability in the /register/password endpoint where password verification results are discarded, allowing any value as the current password. Remote attackers can submit a username with an incorrect current password to overwrite any account credential including the admin account and gain full administrative control.
Description quoted from the CVE record (assigned by VulnCheck, published 2026-09-15).
Weakness: Unverified Password Change
How it can be exploited
Exploitable over the network with low attack complexity with no special attack requirements needing no privileges and no user interaction. Impact: confidentiality high, integrity high, availability none. CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: yes. Technical impact: total.
Public exploit evidence (Exploit Observer)
Exploit Observer found 3 code repositories naming this CVE.
Code repositories that name a CVE are often scanners, copies or fakes, and some are malware. Read the code before running anything.
See all 6 references on Exploit Observer
Live scores
- EPSS
- 0.009
low predicted chance of attack - VEDAS
- 0.987
strong exploit evidence - On CISA KEV
- Not listed
- Detection rule
- Suricata
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| pig-mesh pig | before 4.1.0 | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: 4.1.0.
Vendor guidance:
- Fix commit ce958668 (patch)
How to detect it
Suricata rules (network detection)
1 rule that alert on traffic matching this exploit: VEDAS CVE-2026-91995 Pig Unverified Password Change Authentication Bypass. Add them to your Suricata rule set and reload.
Show the rules
alert http $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"VEDAS CVE-2026-91995 Pig Unverified Password Change Authentication Bypass"; flow:established,to_server; http.method; content:"POST"; http.uri; content:"/register/password"; fast_pattern; nocase; http.request_body; content:"password"; nocase; classtype:web-application-attack; reference:cve,CVE-2026-91995; reference:url,https://www.exploit.observer/?keyword=CVE-2026-91995&match=exact; reference:url,https://subdomain.center/?engine=ammonites&keyword=pig&match=exact; sid:1082202; rev:1;)
CVE-2026-91995.rules on GitHub
References
Vendor advisories and patches
- Fix commit ce958668 (patch)
Exploit code
- Researcher write-up (third-party-advisory, exploit)
Technical analysis and advisories
- GitHub Issue #1249 (content redacted by the maintainer) (issue-tracking)
- SysUserServiceImpl.java at v4.0.0 (technical-description)
- SysRegisterController.java at v4.0.0 (technical-description)
- VulnCheck Advisory: pig before 4.1.0 Unverified Password Change via /register/password (third-party-advisory)
Other references
- https://github.com/pig-mesh/pig (product)
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer, vedas-signatures. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
Supporting partners
