VulnerabilityPublished 20 Aug 2025

CVE-2025-53522: Six Apart Movable Type (Software Edition) · Use of Less Trusted Source

Affects Six Apart Movable Type (Software Edition)Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.0 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 20 Aug 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Six Apart Ltd. Movable Type (Software Edition)	Affected >=8.0.0 <=8.0.6 >=8.4.0 <=8.4.2	Fixed in–

AI-suggested

Immediate upgrade to a patched version of Movable Type once available from Six Apart Ltd. is the most effective mitigation.
In the interim, implement additional validation and filtering on outgoing password reset emails to ensure they are generated only in response to legitimate requests.
Employ email authentication mechanisms such as SPF, DKIM, and DMARC to reduce the risk of email spoofing and improve detection of tampered emails.
Educate users to be cautious of unexpected password reset emails and verify their legitimacy through secondary channels before taking action.
Monitor logs for unusual password reset requests or spikes in reset email activity that could indicate exploitation attempts.
Consider deploying web application firewalls (WAFs) with custom rules to detect and block suspicious password reset requests or malformed inputs targeting the reset functionality.
Review and harden the password reset workflow to include multi-factor authentication or additional verification steps where feasible, reducing the impact of tampered reset emails.

Description

Movable Type contains an issue with use of less trusted source. If exploited, tampered email to reset a password may be sent by a remote unauthenticated attacker.

Impact

For European organizations using Movable Type (Software Edition) within the affected versions, this vulnerability poses a risk primarily to the integrity of user accounts and the trustworthiness of password reset communications. Attackers could send forged or tampered password reset emails, potentially tricking users into resetting passwords under false pretenses or exposing them to phishing attacks. This could lead to unauthorized account access if attackers combine this with credential harvesting or other social engineering tactics. While confidentiality and availability are not directly impacted, the integrity compromise could undermine user trust and lead to reputational damage, especially for organizations relying on Movable Type for public-facing websites or internal communications. Organizations in sectors such as media, publishing, education, and government that use Movable Type could face targeted attacks exploiting this vulnerability. Additionally, the ease of exploitation (no authentication or user interaction required) increases the risk of automated or large-scale abuse. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future attacks.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 20 Aug 2025, 04:48 UTC

Technical details

References

Community reviews

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