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CVE Record

CVE-2025-27426: Firefox Mobile iOS Full Address Bar Spoof Using Server-Side Redirect to internal error page

Malicious websites utilizing a server-side redirect to an internal error page could result in a spoofed website URL. This vulnerability was fixed in Firefox for iOS 136.

MediumCVSS 5.4Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A malicious site could make Firefox for iOS show a misleading address after a redirect to an internal error page. The main business risk is phishing: users may trust the address bar and enter credentials or sensitive information. Mozilla says this was fixed in Firefox for iOS 136.

Executive priority

Treat this as a moderate user-trust and phishing risk, not a server compromise issue. Prioritize routine mobile browser update enforcement and user-awareness controls, especially for executives and staff using Firefox on iOS.

Technical view

CVE-2025-27426 is a Firefox for iOS address bar spoofing issue involving a server-side redirect to an internal error page. It is associated with CWE-601 and has CVSS 5.4. The source data indicates user interaction is required and confidentiality and integrity impact are low.

Likely exposure

Exposure is limited to Firefox for iOS installations where the Mozilla-fixed release is not confirmed. The provided data does not enumerate all affected prior builds, and contains limited version detail beyond the fix in Firefox for iOS 136.

Exploitation context

The source bundle does not show CISA KEV listing or cited evidence of active exploitation. Plausible abuse is phishing or trust deception after a user visits a malicious website. No exploit details are needed to assess risk.

Researcher notes

Evidence supports address bar spoofing through redirect handling into an internal error page. The public bundle does not provide exploit status, detailed affected-version ranges, or additional mitigations beyond Mozilla's fixed version. Avoid assuming impact outside Firefox for iOS.

Mitigation direction

  • Confirm Firefox for iOS is updated to Mozilla's fixed release, version 136.
  • Use mobile device management to enforce browser update compliance where possible.
  • Warn users about credential prompts following unexpected redirects or browser error pages.
  • Monitor Mozilla advisories for any corrected affected-version details or follow-up guidance.

Validation and detection

  • Inventory managed iOS devices for Firefox for iOS version status.
  • Verify Firefox for iOS installations are at version 136 or a later maintained release.
  • Check phishing reports for suspicious redirects involving Firefox for iOS users.
  • Review mobile management exceptions for users allowed to delay browser updates.
Prepared
Confidence
high
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-601: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2025-27426 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
5.4 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
3Timeline events
1ADP providers
3Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
5.4CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N2.82.5CISA-ADP

Vulnerability scoring details

Base CVSS 3.1 score

5.4Medium
CVSS 3.1 vector shape for CVE-2025-27426Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
cvssV3_1other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
MozillaFirefox for iOS136Listed
Weakness

CWE details

CWE-601

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.