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NVD / CVE Program· CNA mozilla

CVE-2020-26955: When a user downloaded a file in Firefox for Android, if a cookie is set, it would have been re-sent during a subsequent file download opera

Noroxi assessment

Priority: Monitor (action score 26/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.83% (FIRST EPSS); higher than 57.8% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: firefox (Alpine:v3.12) 83.0-r0; librewolf (Alpine:v3.21) 83.0-r0.

Low priority for now. Upgrade to firefox (Alpine:v3.12) 83.0-r0; librewolf (Alpine:v3.21) 83.0-r0 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

When a user downloaded a file in Firefox for Android, if a cookie is set, it would have been re-sent during a subsequent file download operation on the same domain, regardless of whether the original and subsequent request were in private and non-private browsing modes. *Note: This issue only affected Firefox for Android. Other operating systems are unaffected.*. This vulnerability affects Firefox < 83.

MediumCVSS 6.5 · v3.1—No exploit Fix available
Published
Dec 8, 2020
Updated
Aug 19, 2026
EPSS
0.8% · 57th percentile

Report tools

JSON

Action score

26

Monitor

Low priority for now.

CVSS
26 / 40 · 6.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.8%

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  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

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When you'll hear from us

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  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mozillafirefox mobile

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • mozilla firefox mobilebefore 83.0

Versions reported by the vendor

Affected version ranges reported by the assigning authority (mozilla). Independent of NVD's CPE analysis and usually ahead of it.

  • Mozilla Firefox

    • < 83affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Alpine:v3.12firefoxbefore 83.0-r083.0-r0
Alpine:v3.21librewolfbefore 83.0-r083.0-r0

Same product

mozilla: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-84135Other issue in Firefox Focus for Android
    39Monitor
  • CVE-2023-49060An attacker could have accessed internal pages or data by ex-filtrating a security key from ReaderMode via the `referrerpolicy` attribute.
    39Monitor
  • CVE-2026-92033Privilege escalation in Firefox for Android
    35Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2020-15671Oct 1, 2020 · When typing in a password under certain conditions, a race may have occured where the InputContext was not being correctly set for the input
    12Monitor
  • ← EarlierCVE-2020-26954Dec 8, 2020 · When accepting a malicious intent from other installed apps, Firefox for Android accepted manifests from arbitrary file paths and allowed de
    17Monitor
  • Later →CVE-2020-26957Dec 8, 2020 · OneCRL was non-functional in the new Firefox for Android due to a missing service initialization.
    26Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
alpine:firefox83.0-r0 · Alpine:v3.12Package registry (OSV)
alpine:librewolf83.0-r0 · Alpine:v3.21Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

No history yet (it accumulates with the daily EPSS job).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
high · data or configuration can be modified
Availability
none
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
High
Availability impact
None

Weakness class (CWE)

CWE-565 · Reliance on Cookies without Validation and Integrity Checking

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (1 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records