An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Change Avatar function.

published 2025-04-17 last yr. modified 2026-06-17 4mo ago also EUVD-2025-11802

cvss: 7.6; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits: 0; none known

An issue in MyBB 1.8.38 allows a remote attacker to obtain sensitive information via the Change Avatar function. NOTE: the Supplier disputes this because of the allowed actions of Board administrators and because of SSRF mitigation.

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CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: last yr. (2025-04-18)

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

yuque.com https://www.yuque.com/morysummer/vx41bz/qu7zyyxr84qno64e referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
CISA ADP	3.1	7.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L
CNA	3.1	7.6	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L

Classification

Weakness

CWE-918 Server-Side Request Forgery

References

yuque.com /morysummer/vx41bz/qu7zyyxr84qno64e
exploit, third-party-advisory
docs.mybb.com /1.8/administration/security/protection/#limit-access-to-private-hosts-and-ip-addresses
mitigation, product

Sources

CVE List CVE-2025-29458
NVD CVE-2025-29458

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.