No exploitation reportedFix available

CVE-2013-2566

Q: Is CVE-2013-2566 actively exploited?

Active exploitation of CVE-2013-2566 has not been confirmed. Its EPSS score was 84.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2013-2566?

CVE-2013-2566 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

No exploitation reported by the sources we read.

Published2013-03-15
WeaknessCWE-326 · CWE-327

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

The RC4 algorithm, as used in the TLS protocol and SSL protocol, has many single-byte biases, which makes it easier for remote attackers to conduct plaintext-recovery attacks via statistical analysis of ciphertext in a large number of sessions that use the same plaintext.

Timeline

dates in UTC

2013-03-1521:55CVE publishedNVD
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2013-2566?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2013-2566?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Oracle http server

Branch	Affected	Fixed in	Source
11.1	= 11.1.1.7.0	no fix published	NVD
11.1	= 11.1.1.9.0	no fix published	NVD
12.1	= 12.1.3.0.0	no fix published	NVD
12.2	= 12.2.1.1.0	no fix published	NVD
12.2	= 12.2.1.2.0	no fix published	NVD

Canonical ubuntu linux

Branch	Affected	Fixed in	Source
12.4	= 12.04	no fix published	NVD
12.10	= 12.10	no fix published	NVD
13.4	= 13.04	no fix published	NVD
13.10	= 13.10	no fix published	NVD

Mozilla firefox

Branch	Affected	Fixed in	Source
25.0	< 25.0.1	25.0.1	NVD
24.1	≥ 24.1.0, < 24.1.1	24.1.1	NVD
17.0	< 17.0.11	17.0.11	NVD

13 more products in the sources.

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

ICSA-22-160-01 CISA20 known affected
Mitsubishi Electric Air Conditioning Systems
AE-200A: Versions 7.97 and prior · AE-200E: Versions 7.97 and prior · AE-200J: Versions 7.97 and prior · +17 more
ICSA-21-075-02 CISA19 known affected
GE UR Family (Update A)
GE Veronva UR B30: <8.10 · GE Veronva UR B90: <8.10 · GE Veronva UR C30: <8.10 · +16 more

Full record on NVD

Fix

Vendor fix CISA ICSA-21-075-02 · 19 productsGE strongly recommends users with impacted firmware versions update their UR devices to UR firmware Version 8.10 or greater to resolve these vulnerabilities. GE provides additional mitigations and information about these vulnerabilities in GE Publication Number: GES-2021-004 at https://www.gegridso…
Mitigation from the vendor CISA ICSA-22-160-01 · 20 productsG-150AD: Replace the air conditioning systems to AE-200J, AE-50J or EW-50J Version 7.98 or later
Mitigation from the vendor CISA ICSA-22-160-01 · 20 productsAG-150A-A: Replace the air conditioning systems to AE-200A, AE-50A or EW-50A Version 7.98 or later
Mitigation from the vendor CISA ICSA-22-160-01 · 20 productsAG-150A-J: Replace the air conditioning systems to AE-200E, AE-50E or EW-50E Version 7.98 or later
Mitigation from the vendor CISA ICSA-22-160-01 · 20 productsGB-50AD: Replace the air conditioning systems to AE-200J, AE-50J or EW-50J Version 7.98 or later
Mitigation from the vendor CISA ICSA-22-160-01 · 20 productsGB-50ADA-A: Replace the air conditioning systems to AE-200A, AE-50A or EW-50A Version 7.98 or later

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

CISA-ADPSSVC decisionnone2026-05-22
OpenCVESSVC decisionnone—
CISA-ADPCVSS 3.15.92026-05-22
NVDCVSS 3.05.9read 2026-10-23
NVDCVSS 2.04.3read 2026-10-23
CISA-ADPweakness (CWE)CWE-3272026-05-22
NVDweakness (CWE)CWE-326read 2026-10-23
FIRST EPSSEPSS score84.4 %read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: 2013-03-15
Last Modified: 2026-06-16
NVD status: Modified

Frequently asked questions

What is CVE-2013-2566?

Is CVE-2013-2566 actively exploited?

Active exploitation of CVE-2013-2566 has not been confirmed. Its EPSS score was 84.4% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2013-2566?

CVE-2013-2566 has a CVSS v3 base score of 5.9 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N.

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